Response Surface Methodology for Optimization of Ultrasound-Assisted Antioxidants Extraction from Blackberry, Chokeberry and Raspberry Pomaces

An investigation of the ultrasound-assisted extraction (UAE) of polyphenol-rich aqueous extracts from blackberry, chokeberry and raspberry pomaces was carried out. The aim of the study was to choose optimal conditions for UAE in order to obtain extracts rich in phenolic compounds. The optimization was carried out based on response surface methodology. The variable conditions were amplitude of ultrasound wave and extraction time, whereas responses were total polyphenol content and antioxidant capacity. Based on the ANOVA analysis, mathematical models were fitted and verified. The most effective conditions of amplitude and time were 98% and 5.00 min, 78% and 10.32 min and 90% and 11.56 min for blackberry pomace, chokeberry pomace and raspberry pomace, respectively. The actual results obtained in optimized conditions were comparable to the results predicted by the models. Additionally, the anthocyanin content in extracts was determined in the high-performance liquid chromatography assay. It was proven that response surface methodology could be a useful tool in the optimization of UAE processes for obtaining polyphenol-rich extracts from berry fruit pomaces.

The effects of high-pressure, enzymatic, and high-pressure-assisted enzymatic treatment on the properties of soluble dietary fibers and their use in jelly prepared with grape waste extract

This study aimed to investigate the physicochemical attributes of soluble dietary fibers (SDFs) of grape, which were isolated after enzymatic (using cellulase [0.1 MPa/60°C/30 min]), high-pressure (HP) (100 MPa/60°C/30 min), or HP-assisted enzymatic treatment (using cellulase [100 MPa/60°C/30 min]), then to evaluate textural properties, color, and microbiological load of jelly prepared using grape waste extract and either pectin or SDF types. HP-assisted enzymatic treatment increased glucose adsorption capacity by more than 50%, and the water-holding capacity of SDF more than twofold as compared to the levels measured in untreated-SDF. After treatments, glucose and galactose contents decreased, whereas fructose, mannose, xylose, arabinose, and rhamnose ratios increased. The arabinose ratio increased more than twice by the effect of HP, whereas the xylose content increased almost fivefold with HP-assisted enzymatic treatment. For the textural properties of jelly, HP-assisted enzymatic treated-SDF provided almost double values in gel strength and adhesiveness than those contributed by untreated-SDF. It was followed by HP-treated SDF jelly. The results showed that HP-assisted enzymatic treatment developed more similar outcomes with enzymatic treatment, rather than HP treatment alone. HP-assisted enzymatic hydrolysis is recommended for treating SDF for use in jelly due to its synergistic effect. PRACTICAL APPLICATION: High-pressure-assisted cellulase treatment provided the best properties to SDF for jelly. In combined treatment, impacts of cellulase treatment were more prominent than HP effects. Therefore, the use of HP assistance for enzymatic hydrolysis shortens the processing time. Moreover, the technological and functional properties (water holding, glucose adsorption capacity, and monosaccharide composition) of the combined treated-fiber can improve. In addition, the color and textural properties of the jelly prepared with this treated-fiber can be enhanced. In this way, it may be possible to obtain a good thickening agent. This material can also be an alternative to pectin.

The characteristics of microwave-treated insoluble and soluble dietary fibers from grape and their effects on bread quality

This study investigated the morphological and hydration properties of untreated and microwave (MW)-treated isolate forms of soluble (SDF) and insoluble dietary fibers (IDF) obtained from grapes. Then, the rheological, textural, and other physical effects of the fibers (5% flour basis) were evaluated on bread quality. For this purpose, grape pomace was valorized as the juice extraction waste. MW significantly improved hydration properties of SDF and IDF by modifying their microstructures (p < .05). SDF had a clean-cut morphology whereas IDF had an indented microstructure with a wrinkled surface. After MW treatment, deep grooves and holes were observed. These variations in the IDF structure were more extensive. DF additions influenced water absorption, mixing tolerance index, dough development time, dough stability, resistance to extension, extensibility, energy of the dough and hardness, cohesiveness, springiness, chewiness, weight loss, specific volume, crust color difference of the bread in comparison with the properties of control samples significantly (p < .05). IDF had especially pronounced effects on the dough and bread characteristics. SDF enrichment provided more comparable results with the control bread than IDF. The originality of this work is to characterize isolated (100% purity) SDFs and IDFs, then discuss their effects on semi (dough) and final (bread) product quality.

The Efficiency of Selected Green Solvents and Parameters for Polyphenol Extraction from Chokeberry (Aronia melanocarpa (Michx)) Pomace

Chokeberry pomace is a potential source of natural colourants, antimicrobial agents, and anti-senescence compounds due to its high polyphenols content. Therefore, this study assessed the efficiency of green solvents (50% ethanol, 50% glycerol, and 100% distilled water, all acidified with 1% citric acid or 1% formic acid) for anthocyanin and total phenolic content (TPC) extraction from lyophilised chokeberry pomace. Extraction was performed in a water bath at 40, 50, and 60 °C for 60 and 120 min, followed by ultrasonic treatment for 15 and 30 min. Based on the results, 50% ethanol + 1% citric acid yielded significantly higher total anthocyanin content in the case of both spectrometric and HPLC measurements (1783 ± 153 mg CGE/100 g DW and 879.5 mg/100 g DW) at 50 °C for 60 min. Citric acids seem more effective compared to formic acid. The highest values of TPC were obtained with 50% glycerol + 1% formic acid at 50 °C for 60 min (12,309 ± 759 mg GAE/100 g DW). This study provides evidence that a substantial quantity of polyphenols, which can potentially be used as a natural food additive, can be efficiently extracted with 50% ethanol + 1% citric acid or 50% glycerol at 50 °C for 60 min from chokeberry pomace.

Orange Pomace and Peel Extraction Processes towards Sustainable Utilization: A Short Review

More than 58 million metric tonnes of oranges were produced in 2021, and the peels, which account for around one-fifth of the fruit weight, are often discarded as waste in the orange juice industry. Orange pomace and peels as wastes are used as a sustainable raw material to make valuable products for nutraceuticals. The orange peels and pomace contain pectin, phenolics, and limonene, which have been linked to various health benefits. Various green extraction methods, including supercritical carbon dioxide (ScCO₂) extraction, subcritical water extraction (SWE), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE), are applied to valorize the orange peels and pomace. Therefore, this short review will give insight into the valorization of orange peels/pomace extraction using different extraction methods for health and wellness. This review extracts information from articles written in English and published from 2004 to 2022. The review also discusses orange production, bioactive compounds in orange peels/pomaces, green extractions, and potential uses in the food industry. Based on this review, the valorization of orange peels and pomaces can be carried out using green extraction methods with high quantities and qualities of extracts. Therefore, the extract can be used for health and wellness products.

Substrate degradation and postbiotic analysis of alternative fiber ingredients fermented using an in vitro canine fecal inoculum model

Many fiber ingredients are used by the pet food industry; however, little data are available regarding the fermentation characteristics of alternative fibers currently being used. The objectives of this study were to determine organic matter disappearance (OMD) and postbiotic production from various fruit and vegetable fiber sources using an in vitro dog fecal inoculum model. Apple pomace (AP), blueberry pomace (BP), cranberry pomace (CP), tomato pomace (TP), and pea fiber (PF) were used as experimental treatments. Inoculum was prepared using freshly voided feces under anaerobic conditions. Predigested fibers were inoculated and incubated for 1, 3, 6, and 12 h at 39ºC. Short-chain fatty acids (SCFA), branched-chain fatty acids (BCFA), total volatile fatty acids (VFA), and OMD were determined for each fiber source and time point in triplicate. After 12 h or incubation, OMD was similar (P>0.05; average of 18.5%) among treatments. Proportionally, acetate was greater for BP and AP (P<0.05; average of 80.1%) than for the other treatments (68.3 to 71.2%). Molar proportions of propionate was greatest (P<0.05) for CP (26.8%) compared to the remaining treatments (13.6 to 20.7%). Butyrate was proportionally greater for PF (7.7%; P<0.05) than for BP and CP (average of 4.8%) and was lowest for AP (3.8%); however, TP was not different from PF (P>0.05; average of 7.25%). Total VFA concentration was highest for AP (P<0.05) followed by TP (1.17 and 0.75 mmol*g -1 of substrate, respectively). Both BP and PF were similar (average of 0.48 mmol*g -1 of substrate) and lower than for TP, with CP having the lowest VFA concentration (0.21 mmol*g -1 of substrate) among all treatments. Additionally, when comparing molar concentrations, AP and TP (average of 0.0476 mmol*g -1 of substrate) had greater butyrate concentrations than did PF (0.0344 mmol*g -1 of substrate). The AP, BP, and TP treatments had both linear and quadratic relationships (Table 7; P<0.05) for acetate, propionate, and butyrate concentrations across time. Cranberry pomace only demonstrated a linear relationship for propionate (P<0.05), whereas acetate and butyrate had quadratic relationships with time. Pea fiber only demonstrated quadratic relationships between acetate, propionate, and butyrate concentrations and time (P<0.05). Overall, the fiber substrates evaluated were marginally to moderately fermentable when incubated for up to 12 h with canine fecal inoculum.

Effect of Edible Coating Enriched with Natural Antioxidant Extract and Bergamot Essential Oil on the Shelf Life of Strawberries

In this study, the effects of the application of edible coatings on the shelf life of the strawberry were evaluated, with the aim of extending the fruit's availability and shelf life while preserving its qualitative characteristics. In particular, the application of edible coatings enriched with a natural antioxidant to strawberries was evaluated for their physicochemical, microbial, and structural properties, during a storage period (up to 14 days) at refrigerated temperature. The experimental plan provided the formulation for edible coatings enriched with different concentrations of a natural antioxidant extract obtained from bergamot (Citrus bergamia Risso) pomace (1, 2.5, and 5%), bergamot essential oil (0.1% v/v and 0.2% v/v), and a synthetic antioxidant, butylated hydroxytoluene (BHT, 100 ppm). Moreover, a control test with untreated strawberries was considered. The enriched gum Arabic coatings provided good results related to the preservation of the qualitative parameters of the strawberries. The samples coated with the antioxidant extract (2.5%, sample D) and bergamot essential oil (0.1%, sample F) showed the best maintenance of the qualitative parameters after 14 days, showing lower decay rates (36% D and 27% F), good acceptability by consumers (between 5 and 6), and good retention of ascorbic acid (>30 mg 100 g^-1).

Varietal Differences in Juice, Pomace and Root Biochemical Characteristics of Four Rhubarb (Rheum rhabarbarum L.) Cultivars

The complex evaluation of varietal biochemical differences in rhubarb juice, pomace and roots is highly useful to develop an efficient processing technology. Research was carried out to compare four rhubarb cultivars (Malakhit, Krupnochereshkovy, Upryamets and Zaryanka) in terms of the quality and antioxidant parameters of juice, pomace and roots. The laboratory analyses showed a high juice yield (75-82%) with a relatively high content of ascorbic acid (125-164 mg L^-1) and other organic acids (16-21 g L^-1). Citric, oxalic and succinic acids accounted for 98% of the total acids amount. The juice of the cultivar Upryamets demonstrated high levels of the natural preservatives sorbic (36.2 mg L^-1) and benzoic acids (11.7 mg L^-1), which are highly valuable in juice production. The juice pomace proved to be an excellent source of pectin and dietary fiber, whose concentrations reached 21-24% and 59-64%, respectively. The total antioxidant activity decreased according to the following sequence: root pulp (161-232 mg GAE g^-1 d.w.) > root peel (115-170 mg GAE g^-1 d.w.) > juice pomace (28.3-34.4 mg GAE g^-1 d.w.) > juice (4.4-7.6 mg GAE g^-1 f.w.), suggesting that root pulp is a highly valuable antioxidant source. The results of this research highlight the interesting prospects of the complex rhubarb plant processing for the production of juice, containing a wide spectrum of organic acids and natural stabilizers (sorbic and benzoic acids), dietary fiber and pectin (juice pomace) and natural antioxidants (roots).

Impact of drying on the bioactive compounds and antioxidant properties of bignay [Antidesma bunius (L.) Spreng.] pomace

Bignay pomace is a processing byproduct that can be a source of bioactive compounds. However, a suitable dehydration method should be considered to efficiently valorize this waste material into high-value food ingredient and maximize its health-promoting properties. Bignay pomace was subjected to convection oven-drying and freeze-drying to investigate the effect of these pre-processing techniques on the physicochemical, bioactives, and antioxidant properties of the samples. Both drying methods significantly (p<0.05) changed the total phenolic and anthocyanin contents of bignay pomace while flavonoids and tannins were not significantly affected. Freeze-drying of samples resulted in higher phenolic content (1742 vs. 1273 mg gallic acid equivalent/100 g DW) and anthocyanin content (496 vs. 223 mg cyanidin-3-glucoside equivalent/100 g DW) than convection oven-drying. Freeze-drying also resulted in higher antioxidant properties based on DPPH, ABTS radical scavenging activity, and FRAP assays. Bignay pomace extract was analyzed through HPLC (with photo-diode array detector) for its phenolic profile and nine compounds were identified, with catechin and epicatechin as the dominant components. HPLC analysis also showed that while the drying process does not influence the phenolic profile of the samples, it significantly affected the concentration of phenolic compounds present. The results of this study showed that freeze-drying is a more viable method to retain the majority of bignay pomace’s functional properties compared to convection oven-drying.

Quality Characteristics of Novel Pasta Enriched with Non-Extruded and Extruded Blackcurrant Pomace

Fruit pomace is a valuable by-product in terms of its chemical composition, which potential might be used through transformation of the pomace into food ingredients. The aim of this work was to assess the effect of partial (5% and 10%) substitution of powdered non-extruded or extruded blackcurrant pomace for semolina in pasta formula on nutritional and technological properties of the final product. The pasta was assessed for chemical composition, DPPH antiradical activity, color, cooking and textural properties. Presence of the by-products in the pasta resulted in increased total dietary fiber content (from 1.89 ± 0.06 up to 10.03 ± 0.15 g/100 g, dwb), fat content (from 1.29 ± 0.01 up to 2.70 ± 0.05 g/100 g, dwb) and DPPH antiradical activity (from 253 ± 15 up to 1037 ± 7 µmol TE/g, dwb), as well as in significantly different color (p < 0.05) as compared to the semolina-only pasta. The optimal cooking time was shortened by 1.0−1.5 min and by 2.0 min in the case of the lower and higher, respectively, level of pasta supplementation. The water absorption decreased by up to 32% in the enriched pasta. In general, the cooking loss remained unchanged. The uncooked product containing the extruded fruit pomace was characterized by significantly higher breaking strength (p < 0.05) as compared to the standard pasta. Presence of the pomace also affected texture of the cooked pasta, increasing its firmness and hardness and, when using the non-extruded pomace, the tensile strength. In our research, we have shown that durum wheat pasta enriched with 5 or 10% of powdered blackcurrant pomace or their extrudates constitute a food product of improved nutritional value and of appropriate textural characteristics, while maintaining culinary properties that meet pasta industry requirements.

Fibre and micronutrient intakes among fruit juice consumers and non-consumers in the UK and France: Modelling the effects of consumption of an orange pomace juice product

BACKGROUND

Fruit intake, including consumption of 100% fruit juice, is generally associated with a better diet quality and overall health. However, fruit and vegetable intakes are below recommendations in many countries.

METHODS

The present study examined fruit juice intake and total energy and nutrient intakes according to juice consumption or non-consumption in participants in the National Dietary and Nutrition Survey Rolling Programme 2014-2016 in the UK (n = 2723) and the Individual and National Study on Food Consumption 2006-2007 (n = 4079) in France. Total energy and nutrient intakes were also estimated for scenarios in which orange juice with pomace was either added to the daily diet or replaced 100% orange juice or beverages containing fruit juice.

RESULTS

Fruit juice consumers had higher intakes of fruits and vegetables than non-consumers, were more likely to reach 5-a-day targets for fruit and vegetable consumption, and had significantly higher intakes of folate, vitamin C, potassium, magnesium, and fibre. Juice consumers also had higher total energy and sugar intakes, but lower body mass index than non-juice consumers. Modelling consumption of orange juice with pomace increased fibre and potassium intakes in orange juice consumers, and also increased fibre, most micronutrients, and 5-a-day achievements in non-juice consumers.

CONCLUSIONS

These national survey results demonstrate that fruit juice consumers in the UK and France had higher intakes of fruits and vegetables than fruit juice non-consumers, and significantly higher intakes of several micronutrients and fibre. Furthermore, modelling of consumption of orange juice with pomace increased fibre and select micronutrient intakes, particularly among fruit juice non-consumers.

Pomegranate Pomace Extract with Antioxidant, Anticancer, Antimicrobial, and Antiviral Activity Enhances the Quality of Strawberry-Yogurt Smoothie

Valorizing the wastes of the food industry sector as additives in foods and beverages enhances human health and preserves the environment. In this study, pomegranate pomace (PP) was obtained from the company Schweppes and exposed to the production of polyphenols and fiber-enriched fractions, which were subsequently included in a strawberry-yogurt smoothie (SYS). The PP is rich in carbohydrates and fibers and has high water-absorption capacity (WAC) and oil-absorption capacity (OAC) values. The LC/MS phenolic profile of the PP extract indicated that punicalagin (199 g/L) was the main compound, followed by granatin B (60 g/L) and pedunculagin A (52 g/L). Because of the high phenolic content of PP extract, it (p ≤ 0.05) has high antioxidant activity with SC50 of 200 µg/mL, besides scavenging 95% of DPPH radicals compared to ascorbic acid (92%); consequently, it reduced lung cancer cell lines' viability to 86%, and increased caspase-3 activity. Additionally, it inhibited the growth of pathogenic bacteria and fungi i.e., L. monocytogenes, P. aeruginosa, K. pneumonia, A. niger, and C. glabrata, in the 45-160 µg/mL concentration range while killing the tested isolates with 80-290 µg/mL concentrations. These isolates were selected based on the microbial count of spoiled smoothie samples and were identified at the gene level by 16S rRNA gene sequence analysis. The interaction between Spike and ACE2 was inhibited by 75.6%. The PP extract at four levels (0.4, 0.8, 1.2, and 1.4 mg/mL) was added to strawberry-yogurt smoothie formulations. During 2 months storage at 4 °C, the pH values, vitamin C, and total sugars of all SYS decreased. However, the decreases were gradually mitigated in PP-SYS because of the high phenolic content in the PP extract compared to the control. The PP-SYS3 and PP-SYS4 scored higher in flavor, color, and texture than in other samples. In contrast, acidity, fat, and total soluble solids (TSS) increased at the end of the storage period. High fat and TSS content are observed in PP-SYS because of the high fiber content in PP. The PP extract (1.2 and 1.6 mg/mL) decreases the color differences and reduces harmful microbes in PP-SYS compared to the control. Using pomegranate pomace as a source of polyphenols and fiber in functional foods enhances SYS's physiochemical and sensory qualities.

Quality Assessment of Waste from Olive Oil Production and Design of Biodegradable Packaging

The use of olive pomace from olive oil production is still insufficient. The lingering olive pomace is harmful to the environment. On the other hand, the world is increasingly polluted with plastic or by-products from the production of biodegradable products. Considering these two problems, the aim of this work was to develop a mixture and create biodegradable disposable tableware characterized by high antioxidant activity. The disposable tableware was made by mixing olive pomace with teff flour or/and sorghum groats and lecithin. Baking was carried out at the temperature of 180 °C. The best variant of the mixture for the preparation of disposable tableware was olive pomace, teff flour, sorghum groats and lecithin. These vessels were the toughest, with low water absorption and had a high antioxidant potential due to the high content of polyphenols and omega acids. Protecting the cups and bowls with beeswax had a positive effect on reducing water absorption.

Finding a Needle in a Haystack: Producing Antimicrobial Cutin-Derived Oligomers from Tomato Pomace

Agro-industrial residues comprise a rich diversity of plant polymers and bioactive compounds, constituting promising sources for the development of materials, including bioplastics, and food supplements, among other applications. In particular, the polyester cutin is abundant in fruit peel, a plentiful constituent of pomace agro-industrial residues. The potential of diverse fruit pomaces as a source for the development of cutin-derived materials/products has been extensively sought out. This study expands the established knowledge: it sets proof of concept for the production of antimicrobial oligomers from cutin-rich materials isolated in a single step from tomato pomaces generated by two remote agro-industries. Specifically, it first analyzed how the chemical signature (nuclear magnetic resonance (NMR) and gas chromatography-mass spectrometry (GC-MS)) of a pomace (and of its major constituents) mirrors that of the corresponding cutin-rich material isolated using an ionic liquid extractant. The cutin-rich materials were then deconstructed (using mild hydrolyses), and the resultant mixtures were chemically characterized and screened for bactericidal activity against Escherichia coli and Staphylococcus aureus. The presence of esterified structures, linear and/or branched, likely comprising dioic acids as a major building block (but not exclusively) is a prerequisite for activity against E. coli but not against S. aureus that was susceptible to monomers as well. Further studies are required to optimize the production of broad bactericidal oligomers from any cutin-rich pomace source, moving ahead toward their circular usage.

Valorization of Grape Pomace and Berries as a New and Sustainable Dietary Supplement: Development, Characterization, and Antioxidant Activity Testing

Grape pomace and berries represent natural sources of phytochemicals that can increase the quality of life of consumers by contributing to the prevention of chronic diseases; thus, the development of a dietary supplement was necessary. The raw material (r.m.) used for the development of the dietary supplement consisted of dried and powdered bilberries (Vaccinium myrtillus L.), red currants (Ribes rubrum L.), and red fermented pomaces (Vitis vinifera L.) from Feteasca Neagra and Cabernet Sauvignon cultivars. The particle size distribution, powder flow, total phenolic content (TPC), HPLC-DAD phenolic profile assessment, and radical scavenging assay (RSA) were employed for the analysis of the raw material. After encapsulation, the average mass and uniformity of mass, the disintegration, and the uniformity of content for the obtained capsules were performed to obtain a high-quality dietary supplement. All the assays performed complied to the compendial requirements and the TPC was determined at 9.07 ± 0.25 mg gallic acid equivalents/g r.m. and RSA at 48.32 ± 0.74%. The highest quantities of phenolic compounds determined were 333.7 ± 0.50 µg/g r.m. for chlorogenic acid, followed by rutin, ferulic acid, and (+)-catechin with 198.9 ± 1.60 µg/g r.m., 179.8 ± 0.90 µg/g r.m. and 118.7 ± 0.75 µg/g r.m., respectively. The results of this study can be used for the manufacturing and assessing of pilot scale-up capsule batches and thinking of quality assurance, we recommend that the industrial batch extracts should be standardized in polyphenols, and the manufacturing process should be validated.

Potential interactions between starch and fruit pomace may impact the expansion ratio of direct expanded extrudates

Due to their dense characteristics, direct-expanded products fortified with insoluble fiber are generally not well accepted. Understanding the interactions between starch and fiber could help to effectively choose and modify ingredients to produce products containing high amounts of fiber. Therefore, this study aims to explain the interplay between two starches (native and waxy corn) and two pomace types (blueberry and cranberry). Blends up to 100% of pomace were extruded using a co-rotating twin-screw extruder. Raw material and milled extrudates were analyzed for their pasting and hydration properties. Fourier-transform infrared (FTIR) and solid-state nuclear magnetic resonance (NMR) spectroscopy were conducted to observe molecular changes. The expansion ratio (ER) significantly decreased as pomace was added and ranged from 3.85 for pure waxy corn starch to approximately 1 for blends that contained 80% pomace. Distinctions between the blends were observed. Particularly, at 20% of pomace inclusion, native corn starch with cranberry pomace showed a significantly higher ER. Different behaviors were also detected during the physicochemical analyses. A nonlinear trend between pomace level and water solubility as well as absorption was observed for native corn starch blends, suggesting that molecular interactions between the biopolymers occur. FTIR and NMR results give no evidence for new covalent bonds; hence, the most likely interactions occurring are hydrogen bonds. In addition to the dilution effect of pomace addition, the enhancement or weakening of such interactions between starch molecules by pomace compounds may reduce the ER.

The Varietal Influence of Flavour Precursors from Grape Marc on Monoterpene and C13-Norisoprenoid Profiles in Wine as Determined by Membrane-Assisted Solvent Extraction (MASE) GC-MS

The winemaking by-product grape marc (syn. pomace) contains significant quantities of latent flavour in the form of flavour precursors which can be extracted and used to modulate the volatile composition of wine via chemical hydrolysis. Varietal differences in grapes are widely known with respect to their monoterpene content, and this work aimed to extend this knowledge into differences due to cultivar in volatiles derived from marc precursors following wine-like storage conditions. Marc extracts were produced from floral and non-floral grape lots on a laboratory-scale and from Muscat Gordo Blanco marc on a winery -scale, added to a base white wine for storage over five to six months, before being assessed using a newly developed membrane-assisted solvent extraction gas chromatography-mass spectrometry (GC-MS) method. The geraniol glucoside content of the marc extracts was higher than that of juices produced from each grape lot. In all wines with added marc extract from a floral variety, geraniol glucoside concentration increased by around 150–200%, with increases also observed for non-floral varieties. The relative volatile profile from extracts of the floral varieties was similar but had varied absolute concentrations. In summary, while varietally pure extracts would provide the greatest control over flavour outcomes when used in winemaking, aggregated marc parcels from floral cultivars may provide a mechanism to simplify the production logistics of latent flavour extracts for use in the wine sector.

Bioactive compounds of Punica granatum L. wastes by high performance liquid chromatography analysis

The massive pomaces of Punica granatum L. exhibit a challenging losses exposure difficulty for the processing industries. The resent study was aimed to investigate the bioactive compounds of pomace extracts to introduce it to different industries such as pharmaceutical, food, medicinal, agricultural etcetera for optimum use. Four different extracts were prepared and the phenolic compounds were quantified using HPLC-DAD. Different amounts of phenolic compounds were detected in the samples including gallic acid, catechin, ellagic acid, rosmarinic acid, hesperidin, p-coumaric acid and chlorogenic acid. Gallic acid was major compound in all studied extracts of pomaces, with the maximum amount belonging to water extract (at 60 °C). The average amount of gallic acid detected in water extract (at 60 °C) of Punica granatum L. was 11.25 mg g^-1dry weight, while it was 3.24 3.02 and 1.09 mg g^-1dry weight for the extracts obtained by distilled water, methanol and methanol 80%, respectively.

for Inclusion in Freeze-Drying Mouthwashes

In this study, the biological activities of four extracts from Vitis vinifera by-products: two pomace extracts, white (WPE) and red (RPE), a canes extract (CE), and their combination (CoE), were evaluated, to be included in freeze-drying mouthwashes formulations. The cytocompatibility and anticancerous potential of the four extracts were tested on three cancerous cell lines, as well as the cytoprotective activity against nicotine-induced cytotoxicity and the antioxidant potential determined on a human gingival fibroblasts (HGF) cell line. Additionally, the anti-inflammatory activity and the antimicrobial activity against several microorganisms from the oral microbiome were tested. Freeze-dried mouthwashes with CoE were prepared and characterized, both as lyophilizates and after reconstitution. The four tested extracts showed the highest cytotoxicity on MDA-kb2 cell line. The antioxidant potential was demonstrated for WPE, RPE, CE, and CoE, both in non-stimulated and H₂O₂ stimulated conditions. The four extracts reduced the levels of proinflammatory cytokines (IL-6, IL-8, and IL-1β) in a dose-dependent manner, confirming their anti-inflammatory activity. The antimicrobial activity of tested extracts was shown against pathogenic bacteria from the oral microbiome. Mouthwashes of CoE with poloxamer-407, xylitol, and different ratios of mannitol were prepared by freeze-drying leading to porous formulations with interesting mechanical properties and reconstitution times.

Correlations between Total Antioxidant Capacity, Polyphenol and Fatty Acid Content of Native Grape Seed and Pomace of Four Different Grape Varieties in Hungary

Grape pomace is a valuable source of various bioactive compounds such as plant-derived polyphenols and polyunsaturated fatty acids (PUFAs). The commercial demand of grape skin and seed powders as nutraceuticals is still growing. However, no distinction is currently made between unfermented native grape seed and grape seed pomace powders regarding their antioxidant activities. Our aim was to find the relationship between the polyphenol and fatty acid content as well as the antioxidant capacity of native and fermented grape seeds of four different grape varieties harvested in the Villány wine region. According to our results, none of the three investigated polyphenols (resveratrol, rutin, quercetin) could be detected in native grape seed samples in correlation with their significantly lower total antioxidant capacities compared to fermented seed samples. Pinot Noir (PN) grape seed pomace samples with the highest resveratrol and oil content showed significantly higher total antioxidant capacity than Cabernet Sauvignon (CS), Syrah (S) and Blue Portugal (BP) samples. Based on the statistical analysis, positive correlation was found between the fatty acid content and the resveratrol concentration in the pomace samples of different grape varieties. In contrast, rutin concentrations were negatively proportional to the fatty acid content of the fermented samples. No significant correlation was found considering the quercetin content of the samples. According to our findings, grape pomace seems a more promising source in the production of nutraceuticals, since it contains polyphenols in higher concentration and exerts significantly higher antioxidant activity than native grape seeds.

Antioxidant Efficacy of Olive By-Product Extracts in Human Colon HCT8 Cells

The production of olive oil is accompanied by the generation of a huge amount of waste and by-products including olive leaves, pomace, and wastewater. The latter represents a relevant environmental issue because they contain certain phytotoxic compounds that may need specific treatments before the expensive disposal. Therefore, reducing waste biomass and valorizing by-products would make olive oil production more sustainable. Here, we explore the biological actions of extracts deriving from olive by-products including olive pomace (OP), olive wastewater (OWW), and olive leaf (OLs) in human colorectal carcinoma HCT8 cells. Interestingly, with the same phenolic concentration, the extract obtained from the OWW showed higher antioxidant ability compared with the extracts derived from OP and OLs. These biological effects may be related to the differential phenolic composition of the extracts, as OWW extract contains the highest amount of hydroxytyrosol and tyrosol that are potent antioxidant compounds. Furthermore, OP extract that contains a higher level of vanillic acid than the other extracts displayed a cytotoxic action at the highest concentration. Together these findings revealed that phenols in the by-product extracts may interfere with signaling molecules that cross-link several intracellular pathways, raising the possibility to use them for beneficial health effects.

Developing an Olive Biorefinery in Slovenia: Analysis of Phenolic Compounds Found in Olive Mill Pomace and Wastewater

The valorization of olive pomace through the extraction of phenolic compounds at an industrial scale is influenced by several factors that can have a significant impact on the feasibility of this approach. These include the types and levels of phenolic compounds that are present, the impact that seasonal variation and cultivar type have on the phenolic compound content in both olive pomace and mill effluents and the technological approach used to process the olive crop. Chemical analysis of phenolic compounds was performed using an HPLC-diode-array detector (DAD)-qTOF system, resulting in the identification of 45 compounds in olive mill wastewater and pomace, where secoiridoids comprised 50–60% of the total phenolic content. This study examined three different factors that could impact the phenolic compound content of these processing streams, including cultivar types typically grown on local farms in Slovenia, the type of downstream processing used and seasonality effects. Olive crop varieties sourced from local farms showed high variability, and the highest phenolic content was associated with the local variety “Istrska Belica”. During processing, the phenolic content was on average approximately 50% higher during two-phase decanting compared to three-phase decanting and the type of compound present significantly different. An investigation into the seasonal effects revealed that the phenolic content was 20% higher during the 2019 growing season compared to 2018. A larger sample size over additional growing seasons is required to fully understand the annual variation in phenolic compound content. The methods and results used in this study provide a basis for further analysis of phenolic compounds present in the European Union’s olive crop processing residues and will inform techno-economic modelling for the development of olive biorefineries in Slovenia.

Pre-Hydrated Berry Pomace in Wheat Bread: An Approach Considering Requisite Water in Fiber Enrichment

Using blackcurrant pomace, for instance, in bread, prevents wasting this by-product of fruit juice production, thereby also taking advantage of its nutritional benefits. This study investigated the effects of blackcurrant pomace incorporation in wheat dough and the quality of the resulting breads. Two concepts were addressed: (a) adjusting the water level based on the dough consistency and (b) preparing pre-hydrated pomace by applying the determined water content prior to dough preparation and using it for bread making. Samples with wholegrain spelt flour were used for additional comparison. This study revealed that instant pomace incorporation with an adjusted water level diminished the dough stickiness and baking loss, but resulted in stiffer dough with delayed proofing and a decreased bread volume. The kneading resistance pointed to continued swelling after kneading, concomitant with a lower amount of available free water. Counteracting the competition for water of the flour components and pomace fiber by applying pre-hydrated pomace turned out to be successful. The deteriorating effects were reduced to a larger extent by pomace hydrated in hot water. Despite a similar composition, the products of wholegrain spelt flour deviated from the pomace formulations as well as from wheat breads (producing the highest water absorption but smallest loaves). As the water absorption of pomace fiber largely influences the product properties, a pre-hydration of pomace to be included in wheat dough can be highly recommended to enhance processing properties and product quality.

Phenolic Compounds Obtained from Olea europaea By-Products and their Use to Improve the Quality and Shelf Life of Meat and Meat Products-A Review

Consumers are interested in consuming clean label foods. Replacing synthetic additives with natural alternatives (especially sources rich in polyphenols) is a valid solution to produce and also preserve foods, especially meat and meat products. Olea europaea leaves and olive pomace and wastewater contain polyphenols that can be explored in this context. In this review, we summarize the main aspects related to the phenolic composition, extraction conditions, antimicrobial potential, and antioxidant activity (in vitro and in vivo) of Olea europaea leaves, olive pomace and wastewater as well as their applications in the production of meat and meat products. This review found evidence that extracts and isolated polyphenols from the Olea europaea tree and olive processing by-products can be explored as natural antioxidant and antimicrobial additives to improve the preservation of meat and meat products. The polyphenols found in these residues (especially oleuropein, hydroxytyrosol and tyrosol) increased the redox state in the main meat-producing animals and, consequently, the oxidative stability of fresh meat obtained from these animals. Moreover, the extracts and isolated polyphenols also improved the shelf life of fresh meat and meat products (as additive and as active component in film) by delaying the growth of microorganisms and the progression of oxidative reactions during storage. The accumulated evidence supports further investigation as a natural additive to improve the preservation of reformulated muscle products and in the production of edible and sustainable films and coatings for fresh meat and meat products.

Valorization of European Cranberry Bush (Viburnum opulus L.) Berry Pomace Extracts Isolated with Pressurized Ethanol and Water by Assessing Their Phytochemical Composition, Antioxidant, and Antiproliferative Activities

Defatted by supercritical CO₂, Viburnum opulus berry pomace (VOP) was subjected to consecutive extraction with pressurized ethanol (E) and water (W) and yielded 23% of VOP-E and 8% of VOP-W, respectively. The major phytochemical groups covering 42 identified and quantified constituents in VOP extracts were organic and phenolic acids, iridoids, quercetin and (epi)catechin derivatives, flavalignans, procyanidins, and anthocyanins. The on-line HPLC-DPPH^•-scavenging assay revealed the presence of numerous antioxidants. VOP-E had a higher total phenolic content, was a stronger antioxidant (equivalent to 0.77, 0.42, and 0.17 g trolox/g in oxygen radical absorbance capacity (ORAC), ABTS, and DPPH assays, respectively), and recovered the major part of phenolics from the pomace; however, both extracts demonstrated similar antioxidant activity in the cellular assay. VOP-E inhibited HT29 cancer cells at non-cytotoxic concentrations. The results of this study revealed that VOP contains valuable phytochemicals possessing antioxidant and antiproliferative activities. Consequently, extracts from VOP substances may be of interest in developing functional ingredients for healthy foods, nutraceuticals, and cosmeceuticals.

Formulation of Orange Juice with Dietary Fibers Enhances Bioaccessibility of Orange Flavonoids in Juice but Limits Their Ability to Inhibit In Vitro Glucose Transport

The effect of formulating orange juice (OJ) with dietary fibers (DFs) on in vitro bioaccessibility of flavonoids and their ability to inhibit glucose transport in Caco-2 cells were investigated on Valencia orange fruit (OF), OJ, and OJ formulated with 1 and 2.8% DFs. DFs were either orange pomace (P) or commercial pulverized citrus pulp fiber (CF). Juice extraction and formulation with CF led to minimal loss of flavonoids compared to formulation with P (474 μmol/100 g for OF vs 315-368 μmol/100 g for OJ and OJ with CF, and 266-280 μmol/100 g for OJ with P). Addition of DFs led to similar or improved flavonoid bioaccessibility compared to OJ (9.5% in OJ vs 7.9-33.4% with DFs) but higher glucose transport in Caco-2 cells (0.45 μmol/min in OJ alone vs 0.64-0.94 μmol/min with DFs). This paradoxical effect was attributed to potential complexation of flavonoids and DFs, preventing flavonoids from interfering with glucose transport.

The Milk Thistle Seed Cakes and Hempseed Cakes are Potential Feed for Poultry

The aims of this work were to summarize the nutritional value of the milk thistle seed cakes and hempseed cakes and describe the influence on selected performance parameters, metabolism and animal health from inclusion of these non-traditional feeds into diets. It seems more appropriate to apply the extract of the bioactive substances complex to the livestock diets than addition of expellers or other forms of plants processing. The seed expellers, etc. mostly worsened the chickens' performance parameters with higher doses in diets, while most of the work using the extract yields had positive results on animal performance.

Strategies for Reuse of Skins Separated From Grape Pomace as Ingredient of Functional Beverages

Wine grape pomace, the by-product of wine making, is a source of polyphenols, metals, and organic acids, and may be exploited for the production of functional beverages. Among red wines, Primitivo and Negramaro varieties possess an interesting amount of polyphenolic compounds and other chemicals. Consequently, study of the biological activity of Primitivo and Negramaro vinification by-products is of great interest as well as optimizing the extraction of its bioactive components. In order to stabilize the grape pomace, different methods of drying grape pomace were tested. After stabilization of the pomace, the grape skins were manually separated from the seeds and any woody parts. The chemical characterizations of acidified alcoholic (methanol/ethanol) and water extracts and either microwave-assisted or ultrasound-assisted extractions of separated grape skins were compared. Besides that, the in vitro antioxidant activity of wine pomace skin extracts was also investigated as Trolox equivalents antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC). Overall, the alcoholic extractions were found to be the most effective for recovering phenolic compounds, when compared with those in water. Ultrasound- and microwave-assisted extraction of pomace skin using acidified water allowed the highest TEAC value. Taking into account the water extraction result, in order to reuse grape pomace skins to produce a functional beverage, we utilized them in combination with black tea, karkadè (Hibiscus sabdariffa L.), or rooibos (Aspalathus linearis Burm.) to produce an infusion. The combination of grape skins and black tea showed the highest ratio of total phenol content to antioxidant activity. Moreover, skin isolated from pomace, with or without black tea infusions, were shown to have anti-inflammatory capacity in human cell culture. Our results raise the value of grape skin pomace as a rich source of bioactive compounds with antioxidant and anti-inflammatory activity and suggest its exploitation as an ingredient for functional beverages.

Distribution of bioactives in entire mill chain from the drupe to the oil and wastes

Industrial olive oil production generates large amounts of by-products, mainly pomaces and wastewaters. The latter, in particular, represents serious environmental problems requiring special treatments prior to disposal. While olive pomace finds use as alternative energy source, wastewaters still remain a task since it is not reusable, representing an additional cost on olive oil for its treatments. This study is a "comprehensive" overview on the distribution of bioactives in entire mill chain from the drupe to the oil and wastes. Identification was achieved through liquid chromatography coupled with mass spectrometry, spectrofotometric and fluorimetric detection. Phenols resulted the most abundant class of substances, with the highest hydroxytyrosol amounts in wastewater (214 mg/kg). Pomace contained a total of 304 mg/kg in terms of bioactives, thus representing a potential food supplement ingredient for functional foods with high nutritional values.

Addition of Olive Pomace to Feeding Substrate Affects Growth Performance and Nutritional Value of Mealworm (Tenebrio Molitor L.) Larvae

The well-recognized efficiency of Tenebrio molitor larvae to convert low quality organic matter into a nutritionally valuable biomass was exploited to manage solid wastes coming from the olive oil industry, which represent a severe environmental challenge in the Mediterranean area. Three organic pomace-enriched substrates (mixtures middlings/pomace 3:1, 1:1, and 1:3) were assessed, together with 100% organic wheat flour and 100% organic middlings as control feeds. A feeding substrate made up of 25% olive pomace and 75% wheat middlings appeared to be the best compromise between growth performance (larval and pupal weights, survival rate, development time) and nutritional properties of mealworm larvae. In fact, larvae fed the 3:1 feed showed the highest dry matter (DM) yield (38.05%), protein content (47.58% DM), and essential/non-essential amino acids ratio (1.16). Fat content (32.14% DM) and fatty acid composition were not significantly different than those of larvae fed more pomace-enriched feeds.

A Design of Experiments Strategy to Enhance the Recovery of Polyphenolic Compounds from Vitis vinifera By-Products through Heat Reflux Extraction

The aim of the present study was to establish the best experimental conditions that lead to the extracts richest in polyphenolic compounds obtained from pomace and canes of Vitis vinifera. In this regard, a D-Optimal design of experiments (DoE) method was applied to investigate the extraction process parameters from each of three materials: red pomace (RP), white pomace (WP) and canes (C). The input variables were the extraction temperature and the ethanol ratio and as response, the total polyphenols content (TPC) was determined. A design space was generated for each of the plant materials and the most concentrated polyphenol extracts were obtained using 50% ethanol at a temperature of 80 °C. Further, the phenolic profiles of the concentrated extracts were detected by LC/MS/MS and the results showed that WP extract was richer in polyphenolic compounds, both flavonoid and phenolic acids, followed by the RP and C extracts. The antioxidant assays revealed that WP and RP extracts exhibited a higher antioxidant activity which correlated to the high content of polyphenols. These findings revealed that RP, WP and C, currently considered agricultural wastes from winery, may be valorized as an important source of natural antioxidants.

Chemical characterization and antioxidant properties of products and by-products from Olea europaea L

The products and by-products of Olea europaea L.: olive fruits (primary agricultural product), oils (primary agro-industrial product), pomaces (agro-industrial processing by-product), and leaves (agricultural practices by-product), are promising sources of bioactive compounds. In the present study, qualitative and quantitative analyses of selected bioactive components in olive fruits, oils, and pomaces were performed. Total polyphenol content and antioxidant activity were analyzed in all samples (humid pomaces 2015: TPP, 26.0 ± 1.5-43.7 ± 3.0 g(GAEq)/kg DW; TEAC/ABTS, 189.5 ± 3.7-388.1 ± 12.0 mmol(Trx)kg DW). Radical (DPPH) quenching potential was analyzed via photometric and EPR methods, obtaining Vis/EPR signal ratio by 1.05 ± 0.45 and 1.66 ± 0.39 for fruits and pomaces, respectively. Through HPLC-UV and HPLC-MS/MS techniques, oleuropein and hydroxytyrosol, as well as selected hydroxycinnamic acids and flavonoids, were identified and quantified in olive fruits and pomaces. The main components were rutin, luteolin, and chlorogenic acid. Cytotoxic assay on fibroblast cells revealed toxic effects for selected extracts at highest tested concentrations (5%).

Rice Flour and Bran Enriched with Blueberry Polyphenols Increases Storage Stability and Decreases Arsenic Content in Bran

A low-cost method utilizing rice co-products to concentrate and stabilize blueberry polyphenols was developed that decreased the arsenic (As) content in rice bran. After concentration at 10 g/L, brown rice flour displayed a higher total anthocyanin content in both blueberry juice (2.7 mg/g) and pomace extract (2.6 mg/g) when compared to white rice flour. Defatted rice bran enriched with blueberry juice (10 g/L) had the highest concentration of polyphenols (16.0 mg/g), and defatted bran enriched with pomace extract had the highest concentration of anthocyanins (5.32 mg/g). Enriched rice flour and bran contained higher levels of anthocyanins when using pomace extracts. Polyphenols and anthocyanins were found to be highly stable at 37 °C in rice flour and bran samples combined with pomace extract. Polyphenol enrichment also produced lower total and inorganic arsenic (i-As) levels in defatted rice bran. Inorganic arsenic (i-As) concentrations in defatted rice bran enriched with blueberry juice and pomace extracts were reduced by 20.5% and 51.6%, respectively. Overall, rice flour and bran that are enriched with polyphenols and anthocyanins from blueberry pomace extracts are shelf and color stable, had low sugar content, and represent unique health-promoting food ingredients.

Hydroxytyrosyl Oleate: Improved Extraction Procedure from Olive Oil and By-Products, and In Vitro Antioxidant and Skin Regenerative Properties

Recently, we identified hydroxytyrosyl oleate (HtyOle) in the by-products of olive oil, pomace and olive mill waste water (OMWW). Herein, we report that HtyOle is more accurately quantified by extracting the phenolic fraction from both matrices by using aqueous methanol (80%). By applying this method, HtyOle was also detected in extra virgin olive oil (EVOO). Since olive oil is used in the preparation of many cosmetic formulations, we explored the antioxidant capacity of HtyOle in human keratinocytes. Formation of reactive oxygen species (ROS) and malondialdehyde (MDA), as well as activity of Glutathione-S-transferase (GST) and superoxide dismutase (SOD) were decreased by HtyOle. In addition to that, microRNAs (miRs) involved in both redox status balance and skin regeneration potential were also tested. The following miRs, hsa-miR-21 and hsa-miR-29a, were increased while has-miR-34a was not affected by HtyOle.

Ultrasound Treatment on Stability of Total and Individual Anthocyanin Extraction from Blueberry Pomace: Optimization and Comparison

Blueberry pomace is abundant in anthocyanins. This work characterized the anthocyanins in blueberry pomace, discussed the stability of anthocyanins under ultrasound treatment, and compared the extraction conditions for different anthocyanin compositions. Thirteen anthocyanins were identified, and malvidin-3-galactoside (18.56%), which represented the most abundant anthocyanin, was selected as the individual analyte. The general linear model univariate analysis revealed that ultrasound-assisted extraction (UAE) resulted in higher recoveries of both total anthocyanins (TA) and individual anthocyanins (IA) when compared with conventional solvent extraction. The optimized extraction conditions for TA and IA were UAE in pure methanol (12.49 mg/g dry weight) at 25 °C for 30 min and UAE in 70% ethanol (3.57 mg/g dry weight) at 40 °C for 40 min, respectively. Moreover, IA was more vulnerable to degradation compared with TA. Therefore, a specific extraction process of IA is significant for monomer preparation, and harsh conditions should be avoided in UAE.

Effects of acute intake of grape/pomegranate pomace dietary supplement on glucose metabolism and oxidative stress in adults with abdominal obesity

A controlled acute, cross-over clinical study (NCT02710461) was performed in order to evaluate the effects on glucose metabolism of a grape/pomegranate pomace dietary supplement in subjects with abdominal obesity (aged 40-60, n = 20). A standard 75 g oral glucose tolerance test (OGTT) was administered alone, together with or 10 h after the consumption of 10 g of the dietary supplement, rich in both extractable (0.4 g) and non-extractable (1.4 g) polyphenols. The dietary supplement did not ameliorate glucose or insulin at any sampling time. No improvement in antioxidant capacity was observed in plasma or urine, concordant with no increased urine polyphenol excretion. A tendency towards improved insulin sensitivity was observed when the product was consumed 10 h before glucose solution. These results suggest that a single realistic dose of grape/pomegranate pomace is not able to clearly improve glucose metabolism; chronic intake remains to be evaluated.

Characterization of tomato processing by-product for use as a potential functional food ingredient: nutritional composition, antioxidant activity and bioactive compounds

Tomato pomace, a by-product generated during tomato processing, was collected at a large tomato processing industry. The by-product was mainly constituted of tomato skin (61.5%), and presented high moisture content (66.58 g.100g^-1 wet basis). Among the nutrients, the highest content was of dietary fibre, followed by proteins and fat (50.74, 20.91, 14.14 g.100g^-1 d.w., respectively). The pomace has high in vitro antioxidation capacity, especially when measured with the TEAC assay (224.81 μmol Trolox equivalent 100g^-1 d.w.). This is due especially to the high amount of lycopene remaining in the by-product after processing (446.9 μg.g^-1 d.w). The waste was fractioned into skin and seed fractions by sedimentation, resulting in the increase of lycopene yield by 55%, when using skin fraction as the source material in place of the whole pomace. This by-product shows great potential for being used as a source of the ingredients of high nutritional value, especially dietary fibre and lycopene.

Isolation and Characterization of Cellulose from Different Fruit and Vegetable Pomaces

A new fractionation process was developed to achieve valorization of fruit and vegetable pomaces. The importance of the residues from fruits and vegetables is still growing; therefore; the study presents the novel route of a fractioning process for the conversion of agro-industrial biomasses, such as pomaces, into useful feedstocks with potential application in the fields of fuels, chemicals, and polymers. Hence, the biorefinery process is expected to convert them into various by-products offering a great diversity of low-cost materials. The final product of the process is the cellulose of the biofuel importance. The study presents the novel route of the fractioning process for the conversion of agro-industrial biomasses, such as pomaces, into useful feedstocks with a potential application in the fields of fuels, chemicals, and polymers. Therefore the aim of this paper was to present the novel route of the pomaces fraction and the characterization of residuals. Pomaces from apple, cucumber, carrot, and tomato were treated sequentially with water, acidic solution, alkali solution, and oxidative reagent in order to obtain fractions reach in sugars, pectic polysaccharides, hemicellulose, cellulose, and lignin. Pomaces were characterized by dry matter content, neutral detergent solubles, hemicellulose, cellulose, and lignin. Obtained fractions were characterized by the content of pectins expressed as galacturonic acid equivalent and hemicelluloses expressed as a xyloglucan equivalent. The last fraction and residue was cellulose characterized by crystallinity degree by X-ray diffractometer (XRD), microfibril diameter by atomic force microscope (AFM), and overall morphology by scanning electron microscope (SEM). The hemicelluloses content was similar in all pomaces. Moreover, all the materials were characterized by the high pectins level in extracts evaluated as galacturonic acid content. The lignins content compared with other plant biomasses was on a very low level. The cellulose fraction was the highest in cucumber pomace. The cellulose fraction was characterized by crystallinity degree, microfibril diameter, and overall morphology. Isolated cellulose had a very fine structure with relatively high crystalline index but small crystallites.

A comparative study on composition and antioxidant activities of supercritical carbon dioxide, hexane and ethanol extracts from blackberry (Rubus fruticosus) growing in Poland

BACKGROUND

Large quantities of blackberry seeds are produced as a pomace during the processing of juice and jam production; this by-product is a very interesting raw material both for oil manufacturing and as a source of bioactive compounds. In this work the composition, yield and antioxidant activity of three types of Rubus fructicosus pomace extracts isolated by liquid extraction using solvents of different polarity, as well with supercritical CO₂ fluid extraction have been compared.

RESULTS

The highest extract yield was reported for Soxhlet extraction using ethanol as a solvent (14.2%). Supercritical carbon dioxide and hexane extracts were characterised by the highest content of phytosterols (1445 and 1583 mg 100 g^-1 of extract, respectively) among which β-sitosterol was the main one, while the concentration of tocopherols, with predominant γ-isomer, was the highest for both hexane and ethanol extracts, being 2364 and 2334 mg 100 g^-1 , respectively. Using a GC-MS method 95 volatiles, in which non-saturated aldehydes were predominant, were identified in the essential oil of seed pomace and in the volatile oil isolated from supercritical extract. The ethanolic extract which is characterised by the highest phenolic content (9443 mg GAE 100 g^-1 ) exhibited the highest antioxidant activity (according to the ABTS^•+ and DPPH^• assays).

CONCLUSION

All pomace extracts examined were of high quality, rich in essential omega fatty acids and with a very high content of bioactive compounds, such as phytosterols and tocopherols. The high nutritional value of extracts from berry seed pomace could justify the commercialisation of specific extracts not only as food additives but also as cosmetic components. © 2017 Society of Chemical Industry.

Bioaccessibility of Polyphenols from Plant-Processing Byproducts of Black Carrot (Daucus carota L.)

Plant-processing byproducts of black carrot represent an important disposal problem for the industry; however, they are also promising sources of polyphenols, especially anthocyanins. The present study focused on the changes in polyphenols from black carrot, peel, and pomace during in vitro gastrointestinal digestion. Total phenolic content (TPC), total monomeric anthocyanin content (TMAC), and total antioxidant capacity (TAC) were determined using spectrophotometric methods, whereas identification and quantification of polyphenols were carried out using UPLC-ESI-MS(E) and HPLC-DAD, respectively. TPC, TMAC, and TAC significantly decreased (23-82%) as a result of in vitro gastrointestinal digestion. Nevertheless, the amount of pomace anthocyanins released at all stages of in vitro gastrointestinal digestion was higher than black carrot anthocyanins, suggesting that pomace may be a better source of bioaccessible anthocyanins. Overall, the current study highlighted black carrot byproducts as substantial sources of polyphenols, which may be used to enrich food products.

Bioactive compounds in pindo palm (Butia capitata) juice and in pomace resulting of the extraction process

BACKGROUND

Pindo palm (Butia capitata, Becc. 1916) is a tropical fruit native to South America and is relatively rich in bioactive compounds. It is often consumed as juice. The aim of this study was, first, to identify the degradation of these compounds by pasteurization and by cold storage (4 °C) of pindo palm juice. Physicochemical properties and concentrations of phenolic compounds, carotenoids and vitamin C have been evaluated on fresh and pasteurized juices. Moreover, another objective was to characterize the nutritional composition and the bioactive compounds of pindo palm pomace, the by-product of juice processing.

RESULTS

The results demonstrated a degradation of carotenoids with pasteurization and a degradation of vitamin C with both pasteurization and cold storage of juices. Furthermore, the evaluation of pindo palm pomace showed that it is relatively rich in total phenols (20.06 g gallic acid equivalents kg(-1) dry matter) and in β-carotene (0.22 g kg(-1) dry matter).

CONCLUSION

Thus, from the nutrition viewpoint, it does not seem interesting to pasteurize juice. On the other hand, extraction of carotenoids and phenolic compounds from the pomace appears to be a relevant process.

Adding Value to Fruit Processing Waste: Innovative Ways to Incorporate Fibers from Berry Pomace in Baked and Extruded Cereal-based Foods-A SUSFOOD Project

This article communicates the set-up of BERRYPOM, a European research project established in the second call of the SUStainable FOOD Production and Consumption (SUSFOOD) network. The project deals with the by-product from berry processing, which is frequently recycled as animal feed, composted or utilized for biogas production. With BERRYPOM it is proposed to analyze the value of berry pomace, to optimize the recovery of bioactive compounds from pomace material, and to incorporate processed berry pomace in cereal-based foods to take advantage of nutritional benefits that originate from its fiber and the content of bioactive substances. Additionally, extraction methods will be evaluated to obtain products rich in phytochemicals, and the influence of processing steps on the antioxidant capacity of pomace will be analyzed. The fiber extracts will then also be utilized in different cereal-based foods and extruded products. As project outcome we expect a substantial increase of knowledge concerning fiber and phytochemicals extraction from berry pomace, its suitability for enhancing nutritional and sensory properties of cereal-based foods, and its effects on the sustainability of the food chain.

Phenolic composition and antioxidant capacity of pomaces from four grape varieties (Vitis vinifera L.)

BACKGROUND

Phenolic compounds are widely distributed secondary metabolites in plants usually conferring them with unique taste, flavour and health-promoting properties. In fruits of Vitis vinifera L., phenolic composition is highly dependent on grape variety. Differential extraction of these compounds from grapes during winemaking is critically associated with wine quality. By-products of winemaking, such as grape pomace, can contain significant amounts of polyphenols. However, information concerning the varietal effect on wine grape pomace is scarce. In this study, pomaces from Sauvignon Blanc (SB), Chardonnay (CH), Cabernet Sauvignon (CS) and Carménère (CA) grape varieties were characterized spectroscopically and by HPLC-DAD analysis.

RESULTS

White grape pomaces (SB and CH) presented higher antioxidant capacities and higher contents of total phenols and total proanthocyanidins compared with red grape pomaces (CS and CA), whereas the latter showed much higher anthocyanin levels and colour intensities. Concentrations of monomeric proanthocyanidins and low-molecular-weight phenols in the four grape pomace varieties were significantly different.

CONCLUSION

Grape pomaces from four varieties showed high but diverse contents of polyphenols and antioxidant capacities. Thus grape pomaces represent an important potential source of polyphenols, which could be useful for nutritional and/or pharmacological purposes.

Remarkable proanthocyanidin adsorption properties of monastrell pomace cell wall material highlight its potential use as an alternative fining agent in red wine production

The existence of interactions between the polysaccharides of vegetal cell walls and proanthocyanins makes this cell wall material an interesting option for its use as a fining agent to reduce the level of proanthocyanins in wines. Pomace wastes from the winery are widely available and a source of cell wall material, and the identification of varieties whose pomace cell walls present high proanthocyanin binding capacity and of processing methods that could enhance their adsorption properties could be of great interest. This study compared the proanthocyanin adsorption properties of pomace cell wall material from three different grape varieties (Monastrell, Cabernet Sauvignon, and Syrah), and the results were compared with those obtained using fresh grape cell walls. Also, the effect of the vinification method has been studied. Analysis of the proanthocyanidins in the solution after reaction with the cell wall material, using phloroglucinolysis and size exclusion chromatography, provided quantitative and qualitative information on the adsorbed and nonadsorbed compounds. A highlight of this study was the observation that Monastrell pomace cell wall material showed a strong affinity for proanthocyanidins, with values similar to that obtained for fresh grapes cell walls, and a preferential binding of high molecular mass proanthocyanidins, so these pomace cell walls could be used in wines to reduce astringency. The use of maceration enzymes during vinification had little effect on the retention capacity of the pomace cell walls obtained from this vinification, although an increase in the retention of low molecular mass proanthocyanidins was observed, and this might have implications for wine sensory properties.