Antioxidant efficacy of potato peels and sugar beet pulp extracts in vegetable oils protection

The Valorization of Potato Peels as a Functional Ingredient in the Food Industry: A Comprehensive Review

Potato peels (PPs) represent a significant agro-industrial by-product with notable potential for valorization due to their rich composition of bioactive compounds, including phenolics, glycoalkaloids, dietary fiber, and essential minerals. This review explores the functional applications of PPs in the food industry by examining their chemical profile, extraction methods, and biological activities. Phenolic compounds, mainly chlorogenic acid and its derivatives, are the most abundant bioactives and contribute to antioxidant and anti-inflammatory properties. Glycoalkaloids, such as α-solanine and α-chaconine, exhibit antimicrobial activity but require careful monitoring due to their potential toxicity, although recent evidence suggests that controlled doses may provide health benefits. The choice of extraction technique influences the recovery of these compounds, with ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) proving to be efficient and environmentally friendly alternatives to conventional methods. The incorporation of PP-derived ingredients into food formulations, including cereal, dairy, meat, and fish products, as well as vegetable oils, has shown promising results in the improvement of nutritional quality, oxidative stability and functional properties. However, challenges remain with regard to the standardization of PP composition, bioavailability of bioactive compounds and their stability within food matrices. Advancing research on PPs will not only contribute to circular economy goals but also provide innovative solutions for the food industry, reinforcing the link between sustainability and human health.

Co-encapsulation of borage seed oil and peppermint oil blends within ultrasound-assisted soy protein isolate/purity gum ultra complex nanoparticles: Fabrication, structural interaction mechanisms, and in vitro digestion studies

This study aimed at co-encapsulating borage seed oil (BSO)- and peppermint oil (PO) blends in ultrasound-assisted complex nanoparticles stabilized by soy protein isolate (SPI) and purity gum ultra (PGU) in different ratios: SPI/PGU-1:0 (NP1), 0:1 (NP2), 1:1 (NP3), 1:3 (NP4), and 3:1 (NP5). The BSO- and PO-loaded SPI/PGU complex nanoparticles (BP-loaded SPNPs) coded as NP4 (SPI-PGU-1:3) revealed a zeta potential of -33.27 mV, a PDI of 0.14, and the highest encapsulation efficiency (81.38 %). The main interactions observed among SPI, PGU, BSO, PO, and a blend of BSO and PO, as determined by FTIR and molecular docking, involved hydrophobic effects, electrostatic attraction, and H-bonding. These interactions played crucial roles in the production of BP-loaded SPNPs. XRD results validated the alterations in the structure of BP-loaded SPNPs caused by varying proportions of SPI and PGU. The thermal capacity of BP-loaded SPNPs (NP4), as determined by TGA, exhibited the lowest amount of weight loss compared to other BP-loaded SPNPs. Morphological results revealed that NP4 and NP5 exhibited a spherical surface and two distinguishable layers, indicating successful coating of PGU onto the droplet surface. In addition, BP-loaded SPNPs (NP4) exhibited a higher antioxidant effect due to their improved progressive release and prolonged release of co-encapsulated BSO and PO during in vitro digestion. The comprehensive investigation of the co-encapsulation of BSO and PO in complex nanoparticles, dietary supplements, and double-layered emulsified systems provides valuable insights into the development of functional foods.

Unveiling the oxidative stability, phytochemical richness, and nutritional integrity of cold-pressed Linum usitatissimum oil under UV exposure

This study examines the effect of UV irradiation on the oxidation stability of Linum usitatissimum oil, presenting possible changes in the phytochemical profile due to photo-oxidation. GC-MS analysis of the oils identified 11 fatty acid compounds with a high percentage of unsaturated fatty acids, the most important of which is α-linolenic acid (ALA), known as omega-3 (48.88 %), also significant profiles of phytosterol and tcocopherol isomers rich in β-Sitosterol and γ-tocopherols respectively. As well as physicochemical properties such as free fatty acids (FFA %), peroxide value (PV) and iodine value (IV), and nutritional indexes that determine the significant changes observed during the oxidation process, the most important of which is the progressive increase in acidity, peroxide, conjugated dienes and trienes and degrees of unsaturation over 8 h of UV exposure. High levels of carotenoids and phenolic compounds (TPC) protect and enhance oil quality in the face of irradiation, so a significantly small difference is observed between irradiated and non-irradiated oil during photo-oxidation.

Improving sunflower oil stability with propolis: A study on antioxidative effects of Turkish propolis during accelerated oxidation

Propolis, a natural resinous substance collected by bees, is known for its potent antioxidant properties. This study investigates the antioxidant activities and total phenolic contents of propolis samples from 16 provinces of Türkiye and their effects on the oxidative stability of sunflower oil. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) inhibition was in the range of 28.1%-92.5% in thirteen propolis samples, whereas this rate was 24.5% in butylated hydroxytoluene (BHT). Although 2,2'-azino-bis(3-ethylbenzotiazolin-6-sulfonic acid) (ABTS) value was 224 µmol trolox/g in BHT, this value was in the range of 262-1370 µmol trolox/g in propolis samples, except for one. Propolis methanol extracts 13 applied to sunflower oil at a concentration of 1000 ppm were more efficient than BHT added at 200 ppm for inhibiting the production of peroxide value (PV). Similarly, most propolis extracts (1000 ppm) demonstrated antioxidant activity against the production of p-anisidine (p-AV) in sunflower oil under accelerated oxidation conditions. It was determined that Turkish propolis had strong antioxidant properties and delayed oxidation and may be utilized commercially in the food sector to delay the oxidation of fats and oils.

Oxidative stability and nutritional quality of stored Linum usitatissmium L. and Argania spinosa L., oil blends: Chemical compositions, properties and nutritional value

Identification of the chemical compositions of fatty acids and tocopherols shows the high content of linum usitatissimum oil (LO) by linolenic acid 55.3735% and γ-tocopherol 570.927 mg/kg, while argania spinosa oil (AO) is known by the dominance of oleic acid 47.77% followed by linoleic acid 31.08% as well as tocopherols by γ-tocopherols 687.485 mg/kg and δ-tocopherols 51.035 mg/kg. This difference in compositions enables us to enrich the low-stability oil and monitor its behavior during storage at a specific time and under specific conditions. In this study, pure linum usitatissimum and argania spinosa oils extracted by cold pressing as well as their formulations at proportions of (LO: AO) respectively: (80:20; 60:40, 50:50; 40:60; 20: 80) were oxidized at 60 °C for 28 days of storage, during which time the pure oils and blends were assessed for oxidative stability by studying their different fatty acid and tocopherol profiles and physicochemical characteristics such as acidity, peroxide value and chlorophyll and carotenoid pigments, as well as nutritional indexes such as the atherogenic index (AI), the thrombogenic index (TI), and the hypocholesterolemic: hypercholesterolemic ratio (HH), ω3:ω6 ratio, also the oxidative susceptibility (OS), and oxidazability value (Cox), and total phenolic compounds (TPC).

The effect of nano/microparticles of bee pollen on the shelf life of high-fat cooked sausage during refrigerated storage

Sausage is susceptible to oxidative changes in lipids and microbial spoilage due to the presence of water, fat, protein, and vitamins. Bee pollen (BP) as a source of potential antioxidants and antibacterial compounds can effectively prevent lipid peroxidation and microbial spoilage in meat products. The aim of the present study was to investigate the antibacterial and antioxidant activities of BP and the effects of nano/microparticles of bee pollen extract (n/m BP) at a concentration of 125 and 250 mg/100 g meat on the oxidative stability and microbial growth of high-fat sausage during 30 days of storage at 4°C. The formation of BP particles in the nano/micro range was confirmed by scanning electron microscopy. High concentrations of total phenolic compounds (28.26 ± 0.10 mg GAE/g BP) with antioxidant activity (EC50 = 5.4 ± 0.07 mg/mL) were detected in BP. Based on the microdilution assay, the minimum inhibitory concentration of n/m BP for all test bacteria was 1000 (μg/mL) and the minimum bactericidal concentration of n/m BP was 2000 (μg/mL) for Staphylococcus aureus and Bacillus cereus and 4000 (μg/mL) for Escherichia coli and Pseudomonas aeruginosa. The n/m BP treatment (250 mg/100 g meat) showed a higher pH value (p < .05) and lower TBARS values (p < .05) than the ascorbic acid treatment (100 mg/100 g meat) and the control during the storage period. The microbial analysis showed that the addition of n/m BP led to a significant decrease (p < .05) in the total bacterial count, coliforms, S. aureus, and fungal population compared to the other samples. The results show that the addition of n/m BP (125 mg/100 g) can improve the texture, taste, and overall acceptability of the sausage compared to the control sample. In conclusion, this study suggests that BP can replace synthetic antioxidants in high-fat sausages at the nano/microparticle level.

Sodium alginate films incorporated with Lepidium sativum (Garden cress) extract as a novel method to enhancement the oxidative stability of edible oil

This study addresses the growing interest in bio-based active food packaging by infusing Lepidium sativum (Garden cress) seeds extract (GRCE) into sodium alginate (SALG) films at varying concentrations (1, 3, and 5 %). The GRCE extract revealed six phenolic compounds, with gallic and chlorogenic acids being prominent, showcasing substantial total phenolic content (TPC) of 139.36 μg GAE/mg and total flavonoid content (TFC) of 26.46 μg RE/mg. The integration into SALG films significantly increased TPC, reaching 30.73 mg GAE/g in the film with 5 % GRCE. This enhancement extended to DPPH and ABTS activities, with notable rises to 66.47 and 70.12 %, respectively. Physical properties, including tensile strength, thickness, solubility, and moisture content, were positively affected. A reduction in water vapor permeability (WVP) was reported in the film enriched with 5 % GRCE (1.389 × 10-10 g H2O/m s p.a.). FT-IR analysis revealed bands indicating GRCE's physical interaction with the SALG matrix, with thermal stability of the films decreasing upon GRCE integration. SALG/GRCE5 effectively lowered the peroxide value (PV) of sunflower oil after four weeks at 50 °C compared to the control, with direct film-oil contact enhancing this reduction. Similar trends were observed in the K232 and K270 values.

Metabolomics Reveals the Response Mechanisms of Potato Tubers to Light Exposure and Wounding during Storage and Cooking Processes

Potato is susceptible to light exposure and wounding during harvesting and transportation. However, the metabolite profile changes in these potato tubers are unclear. The potato cultivars in this study included Hezuo88 (HZ88), Shida6 (SD6), and Jianchuanhong (JCH); the effects of light exposure (L), wounding (W), and the cooking process on potato metabolites were determined. In total, 973 metabolites were identified, with differential metabolites (mainly alkaloids, flavonoids, and phenolic acids) accumulated on days 0 and 2 (0 d and 2 d) in the 0dHZ88 vs. 0dJCH (189), 0dHZ88 vs. 0dSD6 (147), 0dSD6 vs. 0dJCH (91), 0dJCH vs. 2dIJCH (151), 0dJCH vs. 2dWDJCH (250), 0dJCH vs. 2dWLJCH (255), 2dIJCH vs. 2dWDJCH (234), and 2dIJCH vs. 2dWLJCH (292) groups. The flavonoid content in the light exposure group was higher than that in the dark group. The alkaloid content in the wounded group was higher than that in the uninjured potato tuber group, but the lipid content in the wounded group was lower. Importantly, only 5.54% of the metabolites changed after potato tuber steaming. These results provide valuable information for the breeding and consumption of potato tubers.

Enhancing canola oil's shelf life with nano-encapsulated Mentha aquatica extract for optimal antioxidant performance

Incorporation of antioxidants, such as phenolic compounds into edible oils has limitations such as rapid release of phenolic compounds, low solubility, low penetration, low accessibility, and rapid degradation by environmental compounds. To solve this problem, the nano-encapsulation process is offering promising opportunities. In this research, for the first time, the phenolic extract of Mentha aquatica was nano-encapsulated in nano-emulsions coated with chitosan, Lepidium perfoliatum gum (LPG), and complex of chitosan and LPG (CCL) (1:1 ratio). Based on various tests (particle size measurement, ζ-potential, polydispersity index, encapsulation efficiency index, and intensity curve), the LPG coating was the most optimum option for nano-encapsulation compared to the other coatings. Thus, the LPG-assisted nano-encapsulated phenolic extract of M. aquatica was used to improve the oxidative stability of canola oil at three concentrations (100, 200, and 300 ppm). The results of peroxide value and anisidine index tests (as initial and secondary oxidation indicators, respectively) showed that the nano-encapsulation improved the antioxidant effect of M. aquatica when compared with free extract in canola oil. In a comparative approach, the best sample was obtained from the LPG-assisted nano-encapsulated extract (200 ppm) due to the release of more phenolic compounds. The findings from this study showcase how nano-encapsulation enhances the efficacy of antioxidants in edible oils.

Lid Films of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/Microfibrillated Cellulose Composites for Fatty Food Preservation

The present work evaluates the food packaging performance of previously developed films of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) reinforced with atomized microfibrillated cellulose (MFC) compatibilized by a reactive melt-mixing process. To this end, the novel green composite films were originally applied herein as lids in aluminum trays to preserve two dissimilar types of fatty foods, namely minced pork meat and sunflower oil. Results indicated that the PHBV/MFC films effectively preserved the physicochemical and microbiological quality of pork meat for one week of storage at 5 °C. In particular, the compatibilized green composite lid film yielded the lowest weight loss and highest oxidative stability, showing values of 0.935% and 0.78 malonaldehyde (MDA)/kg. Moreover, none of the packaged meat samples exceeded the acceptable Total Aerobial Count (TAC) level of 5 logs colony-forming units (CFU)/g due to the improved barrier properties of the lids. Furthermore, the green composite films successfully prevented sunflower oil oxidation in accelerated oxidative storage conditions for 21 days. Similarly, the compatibilized PHBV/MFC lid film led to the lowest peroxide value (PV) and conjugated diene and triene contents, with respective values of 19.5 meq O₂/kg and 2.50 and 1.44 g/100 mL. Finally, the migration of the newly developed PHBV-based films was assessed using two food simulants, proving to be safe since their overall migration levels were in the 1-3 mg/dm² range and, thus, below the maximum level established by legislation.

Phenolic compounds of sugar beet (Beta vulgaris L.): Separation method, chemical characterization, and biological properties

Sugar beet (Beta vulgaris L.) is a good source of bioactive compounds. However, information on the biological properties of sugar beet root is limited and its beneficial effects have not been completely understood. In this work, 10 phenolic compounds have been separated and identified in various parts of sugar beet for the first time, including the most abundant epicatechin (31.16 ± 1.89 mg/100 g), gallic acid (30.57 ± 2.69 mg/100 g), and quercetin-3-O-rutinoside (30.14 ± 3.63 mg/100 g). The biological activity tests indicated that sugar beet peel potently scavenged the nitric oxide and DPPH (2,2-diphenyl-1-picrylhydrazyl) free radicals with IC50 values of 88.17 ± 05.14 and 28.77 ± 0.62 μg/ml, respectively. In addition, sugar beet peel exhibited the highest reducing power, IC50 values of 11.98 ± 1.20 μg/ml, and the highest ion-chelating activity, IC50 values of 48.52% and 55.21% for cupric and ferrous ions at 250 μg/ml, respectively. Compared to synthetic antioxidants, sugar beet showed promising biological activities, which could be considered further in future studies.

Potential of Low Cost Agro-Industrial Wastes as a Natural Antioxidant on Carcinogenic Acrylamide Formation in Potato Fried Chips

Acrylamide is classified as a toxic and a prospective carcinogen to humans, and it is formed during thermal process via Maillard reaction. In order to find innovative ways to diminish acrylamide formation in potato chips, several extracts of agricultural wastes including potato peels, olive leaves, lemon peels and pomegranate peels extracts were examined as a soaking pre-treatment before frying step. Total phenolic, total flavonoids, antioxidant activity, and the reduction in sugar and asparagine contents were additionally performed. Proximate composition of these wastes was found to be markedly higher in fat, carbohydrate and ash contents. Lemon peels and potato peels showed almost similar phenolic content (162 ± 0.93 and 157 ± 0.88 mg GAE /g, respectively) and exhibited strong ABTS and DPPH radical scavenging activities than the other wastes. The reduction percentage of reducing sugars and asparagine after soaking treatment ranged from 28.70 to 39.57% and from 22.71 to 29.55%, respectively. HPLC results showed higher level of acrylamide formation in control sample (104.94 mg/kg) and by using the wastes extracts of lemon peels, potato peels, olive leaves, and pomegranate peels succeeded to mitigate acrylamide level by 86.11%, 69.66%, 34.03%, and 11.08%, respectively. Thus, it can be concluded that the soaking of potato slices in the tested wastes extracts as antioxidant as pre-treatment before frying reduces the formation of acrylamide and in this way, the risks connected to acrylamide consumption could be regulated and managed.

Metabolic Profiling of Bulgarian Potato Cultivars

Potatoes (Solanum tuberosum L.) are the fourth most economically important crop in the world. They have a short period of vegetation and are an excellent source of carbohydrates, amino acids, vitamins, organic acids, minerals and phenolics as antioxidant substances. Potato can be a major dietary source of various bioactive compounds. In this study, we applied gas chromatography coupled with mass spectrometry (GC-MS) metabolite profiling to classify eight Bulgarian potato cultivars bred in the Maritsa Vegetable Crops Research Institute (VCRI), Plovdiv, according to their metabolite contents. Altogether, we determine their flavonoids/phenolics to evaluate their nutritive quality for the breeding program with the target of determining strong health-promoting compounds. The “Kalina” cultivar is highlighted as the best one with the highest number of metabolites, containing 14 out of the 26 evaluated; it was selected as the highest-quality cultivar, compared with the other seven cultivars studied. According to the grouping of the cultivars in principal component analysis PCA, their positive distribution is explained mainly by them having the highest contents of aminobutyric and isocitric acids, methionine and alanine and lower levels of fumaric acid, pyroglutamic acid and glycine, in contrast to the cultivars distributed negatively, which had high contents of carbohydrates and relatively low contents of most of the amino acids. The highest number of amino acids was found in the cultivar “Kalina”, followed by “Perun” and “Bor”. The highest number of carbohydrates was found in “Pavelsko” and “Iverce”, while the prominent accumulation of organic acids was found in “Kalina”, “Bor” and “Rozhen”. The highest number of flavonoids in the flesh of the tubers was found in the cultivars “Nadezhda” and “Pavelsko”, followed by “Bor”. The highest ratio of flavonoids/phenolics in the flesh was found in “Pavelsko” and in “Nadezhda”, followed by “Iverce”.

Influence of diverse natural biopolymers on the physicochemical characteristics of borage seed oil-peppermint oil loaded W/O/W nanoemulsions entrapped with lycopene

Borage seed oil (BSO), peppermint oil (PO) and lycopene (LC) have accomplished a lot of interest due to their therapeutic benefits in the food and pharmaceutical sectors. However, their employment in functional food products and dietary supplements is still precluded by their high susceptibility to oxidation. Thus, the encapsulation can be applied as a promising strategy to overcome these limits. In the present study, doubly layered water/oil/water (W/O/W) nanoemulsions were equipped using purity gum ultra (PGU), soy protein isolate (SPI), pectin (PC), whey protein isolate (WPI) and WPI-PC and SPI-PC complexes, and their physico-chemical properties were investigated. Our aim was to investigate the influence of natural biopolymers as stabilizers on the physicochemical properties of nanoemulsified BSO, PO and lycopene thru W/O/W emulsions. The droplet size of the fabricated emulsions coated with PGU, WPI, SPI, PC, WPI-PC, and SPI-PC was 156.2, 265.9, 254.7, 168.5, 559.5 and 656.1 nm, correspondingly. The encapsulation efficiency of the entrapped bioactives for powders embedded by PGU, WPI, SPI, PC, WPI-PC, and SPI-PC was 95.21%, 94.67%, 97.24%, 92.19%, 90.07% and 92.34%, respectively. In addition, peroxide and p-anisidine values were used to measure the antioxidant potential of the entrapped bioactive compounds during storage, which was compared to synthetic antioxidant and bare natural antioxidant. The collected findings revealed that oxidation occurred in oils encompassing entrapped bioactive compounds, but at a lower extent than for non-encapsulated bioactives. In summary, the findings obtained from current research prove that the nanoencapsulation of BSO surrounded by innermost aqueous stage of W/O/W improved its stability as well as allowed a controlled release of the entrapped bioactives. Thus, the obtained BSO-PO-based systems could be successfully used for further fortification of food-stuffs.

Utilization of Vegetable and Fruit By-products as Functional Ingredient and Food

With the constant growth of the human population, the global demand for food is increasing annually. Food security is an arising issue due to decreased resources and massive waste production from the agricultural sector. For example, not all parts of fruits and vegetables are consumed by consumers, and this phenomenon can lead to huge amounts of food wastes that are produced globally. Moreover, non-utilized agriculture by-products, including seed coat, hull, husk, peels, seeds, and pomace, can cause environmental issues. Hence, efficiently utilizing food wastes, such as vegetable and fruit by-products, could be a way to increase food sustainability, and in line with the United Nations Sustainable Development Goal (SDG) to ensure sustainable consumption and production patterns. Moreover, certain agriculture by-products are reported to have a high nutritional value and could be potentially used as functional ingredient and food in the food industry. This review article summarizes findings on the development of new functional foods by utilizing different types of agriculture by-products, that is, vegetable and fruit by-products as ingredients. Furthermore, the nutritional values, processing methods, product acceptability, and potential uses of these vegetable and fruit by-products are also discussed. These by-products can be an alternative source of nutrients to support the global demand for functional foods and as one of the strategies to cope with food insecurity. Studies have shown that different types of fruit and vegetable by-products were well-incorporated in the development of functional foods, such as bakery products and dairy products. Of great importance, this review article provides an insight of the nutritional value, health benefits, and utilization of fruit and vegetable by-products.

Onion (Allium cepa L.) peel extracts characterization by conventional and modern methods

The impact of different extraction methods on bioactive compounds (total phenols and flavonoids) recovery from onion wastes recovered from the market was investigated. The results revealed a total polyphenol content from 25.19 ± 3.56 mg gallic acid equivalents/g for enzyme-assisted extraction (EAE) to 212.56 ± 1.18 mg gallic acid equivalents/g for supercritical extraction (SFE). The total flavonoid content registered from 108.36 ± 3.62 mg quercetin equivalents/g for EAE to 334.97 ± 19.41 mg quercetin equivalents/g for conventional solvent extraction (CSE). The antioxidant activity (404.93 ± 1.39 mM Trolox/g) for SFE was the highest compared to all the extraction procedures used. The chromatographic profiles were conducted at five primary compound identification (quercetin 7,4-diglycoside, quercetin 3,4-diglycoside, quercetin 4-glucoside, quercetin, and kaempferol) and GC-MS analysis allowed the identification of 26 compounds, manly identified in EAE. The results also revealed that the SFE method, as a non-invasive technique, recorded the highest concentration of bioactive compounds and antioxidant activity, confirmed by chromatographic profiles.

The Use of Salvia macrosiphon and Lepidium sativum Linn. Seed Gums in Nanoencapsulation Processes: Improving Antioxidant Activity of Potato Skin Extract

In the present study, the effect of Salvia macrosiphon Seed Gum (SMSG) and Lepidium sativum Linn. Seed Gum (LSSG) as a coating agent on the properties of nanoencapsulated potato skin extract was studied. Moreover, the antioxidant effect of nanoencapsulated extract at a concentration of 1000 ppm incorporated into soybean oil was evaluated. The Z-average size of the emulsions stabilized by SMSG; LSSG; and a complex (1 : 1) of SMSG and LSSG (CSL) was estimated as 160.2, 144.3, and 115.2 nm. The encapsulation efficiency of phenolic extracts in the powders formed by SMSG, LSSG, and CSL was 82.39, 81.67, and 93.6% which declined to 45.28, 48.22, and 62.67% after storage for 40 days at 30°C. The results indicated that the use of coating agents for encapsulation enhanced their antioxidant effect and compared with TBHQ and free extract that nanoencapsulated extract by CSL had the highest antioxidant activity followed by LSSG nanoencapsulated extract and SMSG nanoencapsulated extract.

The application of polyphenols in food preservation

Polyphenols are a kind of complex secondary metabolites in nature, widely exist in the flowers, bark, roots, stems, leaves, and fruits of plants. Numerous studies have shown that plant-derived polyphenols have a variety of bioactivities due to their unique chemical structure, such as antioxidant, antimicrobial, and prevention of chronic diseases, cardiovascular disease, cancer, osteoporosis, and neurodegeneration. With the gradual rise of natural product development, plant polyphenols have gradually become one of the research hotspots in the field of food science due to their wide distribution in the plants, and the diversity of physiological functions. Owing to the extraordinary antioxidant and antibacterial activity of polyphenols, plant-derived polyphenols offer an alternative to chemical additives used in the food industry, such as oil, seafood, meat, beverages, and food package materials. Based on this, this chapter provides an overview of the potential antioxidant and antibacterial mechanisms of plant polyphenols and their application in food preservation, it would be providing a reference for the future development of polyphenols in the food industry.

Development of walnut oil and almond oil blends for improvements in nutritional and oxidative stability

For the increase in oxidative stability and phytonutrient contents of walnut oil (WO), 5, 10, 20 and 30% blends with almond oil (AO) were prepared. The fatty acid compositions and the micronutrients of the oil samples such as tocopherol, phytosterol and squalene were measured by GC-MS and HPLC. It was found that the proportions of PUFAs/SFAs in blended oils with high AO contents were lowered, and the blends contained higher levels of tocopherols, phytosterols and squalene than those of pure WO. The 60 °C oven accelerated oxidation test was used to determine the oxidative stability of the blended oil. The fatty acid composition, micronutrients and oxidation products were determined. The results showed that the oxidation stability of the blended oil increased with an increasing proportion of AO. In addition, a significant negative correlation between micronutrient and oxidation products was observed as the number of days of oxidation increased.

Effect of Star Fruit (Averrhoa carambola L.)By-product on Oxidative Stability of Sesame (Sesamum indicum) Oil under Accelerated Oven Storage and during Frying

Aim of this study was to evaluate the effect of star fruit (Averrhoa carambola L.) by-products (peel and residue) on stability of sesame (Sesamum indicum) oil against oxidation. Antioxidant properties of extract of peel and residue at different time durations of extraction were determined and found that peel contains higher antioxidant potential than residue. Thus, extract of peel obtained after 24 h extraction was used to study its effectiveness on oxidative stability of sesame oil during accelerated oven storage and frying using the butylated hydroxytoluene (BHT) (200 ppm) as the reference antioxidant (positive control) and oil without added antioxidant as the negative control. The oxidative stability of the oil was determined by evaluating peroxide value, p-anisidine value, thiobarbituric acid reactive substances (TBARS) value, total oxidation (TOTOX) value, conjugated diene (CD) and conjugated triene (CT) values, and iodine value. Peel extract at different concentrations (200-1000 ppm) was tested. The oil added with peel extract exhibited higher stability against oxidation than the controls during oven storage test. Extract at 1000 ppm significantly increased the stability of sesame oil during frying as compared with controls. Thus, star fruit peel extract could be an alternative to synthetic antioxidants to suppress oxidation of edible oils.

Phenolic acids from vegetables: A review on processing stability and health benefits

Phenolic acids are the most prominent group of bioactive compounds present in various plant sources. Hydroxybenzoic acids and hydroxycinnamic acids, the aromatic secondary metabolites imparting typical organoleptic characteristics to food are the major phenolic acids, and they are linked to several health benefits. Fruit and beverage crops being the richer sources of phenolic acids have been studied in depth, but phenolic acids from vegetables are largely overlooked. Though lesser in quantity in many vegetables, there is a need to explore the health benefits of the phenolic acids present in them. In this review, the importance of vegetables as a significant source of phenolic acids is emphasized. Vegetables being easily accessible throughout the year and consumed in larger quantities compared to fruits in our daily diet will probably contribute to significant health benefits. Since vegetables are often processed before consumption, the changes in phenolic acids as influenced by processing methods are highlighted. Best processing methods, pre-treatments and storage conditions for higher retention of phenolic acids have been highlighted to minimize their losses. The phenolic acids in vegetables and their health benefits have been cluster mapped, which may facilitate further research for nutraceutical development for specific health concerns. The processing stability of phenolic acids coupled with higher consumption indicates that they may be a potential source of phenolic acids in the diet. It is expected that the popularization of vegetables as a source of phenolic acids in daily diet will help in ameliorating the adverse effect of some of the lifestyle diseases.

Bioactivity of Selected Phenolic Acids and Hexane Extracts from Bougainvilla spectabilis and Citharexylum spinosum on the Growth of Pectobacterium carotovorum and Dickeya solani Bacteria: An Opportunity to Save the Environment

Phenolic acids and natural extracts, as ecofriendly environmental agents, can be used as bio bactericides against the growth of plant pathogenic bacteria. In this study, isolation trails from infected potato tubers and stems that showed soft rot symptoms in fields revealed two soft rot bacterial isolates and were initially identified through morphological, physiological, and pathogenicity tests. The molecular characterization of these isolates via PCR, based on the 16S rRNA region, was carried out by an analysis of the DNA sequence via BLAST and Genbank, and showed that the soft rot bacterial isolates belong to Pectobacterium carotovorum subsp. carotovorum (PCC1) and Dickeya solani (Ds1). The in vitro results of the tested phenolic acids against the cultured bacterial isolates proved that concentrations of 800, 1600, and 3200 μg/mL were the most effective. Ferulic acid was the potent suppressive phenolic acid tested against the Ds1 isolate, with an inhibition zone ranging from 6.00 to 25.75 mm at different concentrations (25–3200 μg/mL), but had no effect until reaching a concentration of 100 μg/mL in the PCC1 isolate, followed by tannic acid, which ranged from 7.00 to 25.50 mm. On the other hand, tannic acid resulted in a significant decrease in the growth rate of the PCC1 isolate with a mean of 9.11 mm. Chlorogenic acid was not as effective as the rest of the phenolic acids compared with the control. The n-hexane oily extract (HeOE) from Bougainvillea spectabilis bark showed the highest activity against PCC1 and Ds1, with inhibition zone values of 12 and 12.33 mm, respectively, at a concentration of 4000 μg/mL; while the HeOE from Citharexylum spinosum wood showed less activity. In the GC/MS analysis, nonanal, an oily liquid compound, was found ata percentage of 38.28%, followed by cis-2-nonenal (9.75%), which are the main compounds in B. spectabilis bark HeOE, and 2-undecenal (22.39%), trans-2-decenal (18.74%), and oleic acid (10.85%) were found, which are the main compounds in C. spinosum wood HeOE. In conclusion, the phenolic acids and plant HeOEs seem to raise the resistance of potato plants, improving their defense mechanisms against soft rot bacterial pathogens.

Influence of Sumac Extract on the Physico-chemical Properties and Oxidative Stability of Some Cold Pressed Citrus Seed Oils

The acidity values changed between 1.03 mgKOH/100g (control) and 1.11 mgKOH/100g (0.1% extract) for orange oil, 1.06 mgKOH/100g (0.5% extract) and 1.13 mgKOH/100g (0.1% extract) and 1.25 mgKOH/100g (0.5% extract) and 1.31 mgKOH/100g (control) for mandarin oil. The peroxide values were determined between1.37 meqO₂/kg (0.5% extract) and 1.43 meqO₂/kg (0.1% extract) for orange oil, between 1.24 meqO₂/kg (control) and 1.27 meqO₂/kg (0.1% extract) for lemon and 1.60 meqO₂/kg (0.5% extract) and 1.71 meqO₂/kg (control) in mandarin oil samples. The viscosity values of samples changed between 0.051 Pa.S (control) and 0.065 Pa.S (0.5% extract) for orange, 0.051 Pa.S (control) and 0.067 Pa.S (0.5% extract) lemon and 0.044 Pa.S (control) and 0.057 Pa.S (0.5% extract) in mandarin oil samples. At the end of storage study (28^th day), the acidity values significantly changed, and their values ranged between 2.28 mgKOH/100g (0.5% extract) and 3.64 mgKOH/100g (control) in orange, 1.67 mgKOH/100g (0.5% extract) and 2.28 mgKOH/100g (control) in lemon and 1.74 mgKOH/100g (0.5% extract) and 2.36 mgKOH/100g (control) in mandarin oil samples. While peroxide values vary between 11.68 meqO₂/kg (0.5% extract) and 32.57 meqO₂/kg (control) for orange, 12.55 meqO₂/kg (0.5% extract) and 34.63 meqO₂/kg (control) for lemon and between 17.56 meqO₂/kg (0.5% extract) and 37.81 meqO₂/kg (control) for mandarin oils, viscosity values after 28 day storage changed between 0.123 Pa.S (0.5% extract) and 0.675 Pa.S (control) in orange, 0.257 Pa.S (0.5% extract) and 0.697 Pa.S (control) in lemon and 0.215 Pa.S (0.5% extract) and 0.728 Pa.S (control) in mandarin oil samples.

Pomegranate peel methanolic-extract improves the shelf-life of edible-oils under accelerated oxidation conditions

Natural antioxidants extracted from agri-waste resources have gained increased economic, sustainable, and health attention due to their sustainability, safer food-applications, and beneficial components. Pomegranate peel extracts (Punica Granatum L.) have natural phytochemicals with superior protective effects stabilizing a variety of the most common vegetable oils consumed globally. Among five different pomegranate peel extracts, methanolic extract has maximum total phenolic content of 18.89%, a total flavonoid content of 13.95 mg QE kg-1, and a relative antioxidant activity of 93% when compared to other pomegranate peel extracts. Additionally, the HPLC analysis of pomegranate peel methanolic extract exhibited the maximum number of phenolic and flavonoid fractions. HPLC fractions showed that pyrogallol and ellagic acids were the most abundant phenolic compounds with 453 and 126 mg kg-1, respectively. In terms of flavonoid fractions, hesperidine and quercetrin were the highest detected-flavonoids with about 50 and 35 mg kg-1, respectively, from HPLC flavonoids fractions. Therefore, pomegranate peel methanolic extract was selected at different concentrations (100, 200, 400, and 600 ppm) for the stabilizing experiment of Egyptian freshly refined edible oils (sunflower, soybean, and corn oils) in comparison with synthetic antioxidant (tert-butyl hydroquinone TBHQ-200 ppm) during accelerated storage at 70°C for 10 days. The results from the accelerated storage experiment indicated that pomegranate peel methanolic extract (at different concentrations: 200, 400, and 600 ppm) exhibited stronger antioxidant capability in all tested oils rather than negative controls (without antioxidant) and synthetic antioxidant TBHQ-200. Under accelerated oxidation conditions, pomegranate peel methanolic extract have the potential capability to improve the shelf life of edible oils in comparison with the most powerful synthetic antioxidant (TBHQ-200 ppm).

Effect of Ultrasound-Treated Arabinoxylans on the Oxidative Stability of Soybean Oil

Arabinoxylans (AX) are polysaccharides with antioxidant activity and emulsifying properties, which make them an attractive alternative for its potential application as a natural antioxidant in oils. Therefore, this work aimed to investigate the effect of ultrasonic treatment of AX on their antioxidant capacity and its ability to improve the oxidative stability of soybean oil. For this purpose, AX were exposed to ultrasonic treatment at 25% (100 W, AX-1) and 50% (200 W, AX-2) power and an operating frequency of 20 KHz during 15 min, and their macromolecular properties (weight average molecular weight (Mw), polydispersity index and intrinsic viscosity) were evaluated. The antioxidant capacity of AX was determined by the DPPH assay and Rancimat test. Results showed that ultrasonic treatment did not affect the molecular identity of the polysaccharide but modified its Mw distribution. AX-1 showed the highest antioxidant activity (75% inhibition) at 533 µg/mL by the DPPH method compared to AX and AX-2. AX at 0.25% (w/v) and AX-1 at 0.01% (w/v) exerted the highest protective effects on oxidative stability of soybean oil with induction periods of 7.69 and 5.54 h, respectively. The results indicate that AX could be a good alternative for the potential application as a natural antioxidant in oils.

Recovery of Natural Antioxidants from Agro-Industrial Side Streams through Advanced Extraction Techniques

Large amounts of agro-industrial waste are being generated each year, leading to pollution and economic loss. At the same time, these side streams are rich source of active compounds including antioxidants. Recovered compounds can be re-utilized as food additives, functional foods, nutra-/pharmaceuticals, cosmeceuticals, beauty products, and bio-packaging. Advanced extraction techniques are promising tools to recover target compounds such as antioxidants from agro-industrial side streams. Due to the disadvantages of classical extraction techniques (such as large amounts of solvents, increased time of extraction, large amounts of remaining waste after the extraction procedure, etc.), and advanced techniques emerged, in order to obtain more efficient and sustainable processes. In this review paper aspects regarding different modern extraction techniques related to recovery of antioxidant compounds from wastes generated in different industries and their applications are briefly discussed.

Production performance, egg quality, blood biochemical constituents, egg yolk lipid profile and lipid peroxidation of laying hens fed sugar beet pulp

The effect of including sugar beet pulp (SBP) in laying hen diets on performance, egg quality, blood chemistry and egg lipid peroxidation was studied. A total of 200 laying hens were randomly assigned into 4 groups and were offered diets containing SBP at the level of 0%, 3%, 5%, and 7%. The dietary inclusion of SBP linearly (P < 0.01) increased feed intake, egg production, egg weight and mass, and improved feed conversion ratio, yolk color core and Haugh unit. Eggs laid by hens receiving SBP had linearly (P < 0.01) greater protein and lower ether extract. Dietary inclusion of SBP linearly (P < 0.01) decreased egg yolk malondialdehyde, cholesterol, and triglyceride, while increased glutathione peroxidase. Laying hens fed SBP had lower (P < 0.01) serum total lipids, cholesterol, alanine aminotransferase, aspartate aminotransferase, and creatinine. Dietary inclusion of SBP could improve hen performance, health, egg quality, and egg shelf life.

Enhancement of Composition and Oxidative Stability of Chia (Salvia hispanica L.) Seed Oil by Blending with Specialty Oils

Chia seed (Salvia hispanica L.) oil is mainly composed of ω-3 fatty acids (61% to 70%). Despite being nutritionally favorable, higher amounts of polyunsaturated fatty acids result in poorer oxidative stability. Thus, the aim of this work was to produce edible vegetable oil blends rich in ω-3 fatty acids and with greater oxidative stability than pure chia oil. Blending of chia with other specialty oils (walnut, almond, virgin, and roasted sesame oils) was assessed in the following respective proportions: 20:80, 30:70, and 40:60 (v/v). An accelerated storage test was conducted (40 ± 1 °C, 12 days). Primary and secondary oxidation products, free fatty acid content, antioxidant compounds, fatty acid composition, and induction time were determined. The blends presented higher oxidative stability indices than chia oil. Sensory analysis showed that, given a pure oil, judges did not identify statistically significant differences among the blends. The results suggest that blending of chia oil is an adequate alternative to obtain ω-3-enriched oils with higher oxidative stability indices. PRACTICAL APPLICATION: Vegetable oil blending is a widely used practice in the edible oil industry to produce blended oils with enhanced stability and nutritional and sensory properties at affordable prices. The blends developed in this study from chia, sesame, walnut, and almond oils take advantage of the properties of each parent oil to yield products with improved oxidative stability, essential fatty acid presence, and sensory characteristics. To achieve a daily intake of 2.22 g/day of ω-3 fatty acids as recommended by the Intl. Society for the Study of Fatty Acids and Lipids (ISSFAL), it is necessary to consume approximately one spoonful of the formulated mixtures.

Utilization of potato peel as eco-friendly products: A review

An eco-friendly product has been the primary agenda of twenty-first century of the global scientists. One of the main focuses is by-product recycling of food processing industries. It has been long time since food industry byproduct converted into energy and value added products. Potato processing is newly emerging food processing factories in developing countries, and potato is the fourth important crop globally. A dramatic food demand increment had shown in the past two decades. This leads to increase the number of food processing industries. Nowadays, food processing industries particularly processed potato manufactures are expanding and generate a huge volume of potato peel. This by-product causes environmental pollution due to decomposition. However, food byproducts like potato peel have essential organic matter. So this review introduces the potential use of potato peel as food preservative, pharmaceutical ingredient, renewable energy, and animal feed to promote eco-friendly food industries.

Bioactive lipids, antiradical activity and stability of rosehip seed oil under thermal and photo-induced oxidation

In the present report, the fatty acids, tocopherols, and sterol profiles as well as the total phenolics and carotenoids of rosehip (Rosa canina) seed oil were determined. The major fatty acids in the oil were linoleic and linolenic acids, comprising 54.80% and 23.47% of the total fatty acids, respectively. Other bioactive lipids in the oil included total tocopherols (786.3 mg/kg), total phenolics (37.97 mg/kg) and total carotenoids (218.8 mg/kg). Rosehip oil was rich in γ-tocopherol (472.0 mg/kg) and β‑sitosterol (78.0% of total sterols). The DPPH· (2,2′-diphenyl-1-picrylhydrazyl) radical scavenging activity of the oil showed 1.08 mg α-tocopherol/g oil and 4.18 μmol TEAC (Trolox equivalent antioxidant capacity)/g oil, respectively. The ABTS+ (2,2′-Azino-bis-3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activity of the oil showed 1.00 mg α-tocopherol/g oil and 3.02 μmol TEAC/g oil, respectively. The induction period (IP) of the oil was 3.46 h for the Rancimat test (110 °C), while the IP of oil in differential scanning calorimetry (DSC) test (100-150 °C) ranged between 0.26 and 58.06 min. The oxidative stability of the oil was determined under thermal and photo oxidation conditions. The progression of oxidation at 30 °C (under UV light) and at 60 °C (in the dark) was followed by recording the ultraviolet absorption (K232 and K270) and degradation of total tocopherols, γ-tocopherol and total carotenoids. Rapid deterioration occurred in the oil stored under UV light conditions. The information provided in the present work is of importance for using rosehip seed oil in different food and non-food applications.

Influence of main emulsion components on the physicochemical and functional properties of W/O/W nano-emulsion: Effect of polyphenols, Hi-Cap, basil seed gum, soy and whey protein isolates

In this study, the effect of natural macromolecules as carrier agents on the biological activity of nano-encapsulated Bene hull polyphenols (Pistacia atlantica subsp. Mutica) through W/O/W emulsions was evaluated. The W/O microemulsions as primary emulsions and a complex of soy protein isolate and basil seed gum (SPI-BSG), whey protein isolate and basil seed gum (WPI-BSG) and also Hi-Cap 100 in the outer aqueous phase were used to produce W/O/W nano-emulsions. Z-average size of emulsions stabilized by Hi-Cap, WPI-BSG, and SPI-BSG was 318, 736.9 and 1918 nm, respectively. The encapsulation efficiency of polyphenols for powders produced by Hi-Cap, WPI-BSG, and SPI-BSG was 95.25, 90.9 and 92.88%, respectively, which was decreased to 72.47, 67.12 and 64.44% after 6 weeks storage at 30 °C. The antioxidant activity of encapsulated polyphenols at 100, 200 and 300 ppm was measured in oil by peroxide and p-anisidine values during storage and was compared to non-encapsulated extract and synthetic antioxidant. Results showed oxidative alterations in oils containing encapsulated polyphenols was lower than unencapsulated form, which among them capsules produced by SPI-BSG exhibited higher antioxidant effects due to the better gradual release. Generally, the higher antioxidant potential was achieved with increased solubility and controlled release of polyphenols through their nano-encapsulation.