Storage stability of the phenolic compounds, color and antioxidant activity of jambolan juice powder obtained by foam mat drying

Evaluation of the Shelf life of Ready-to-Eat Fresh Bamboo Sprouts (Phyllostachys edulis) Packaged in a Modified Atmosphere or Vacuum: A Comparative Study

During the last decades, the consumption of bamboo sprouts (Phyllostacys edulis) has increased because they are considered a "superfood". However, this product is characterized by a short shelf life due to the deterioration in quality parameters. The aim of this study was to investigate the application of two modified atmosphere packaging (MAP) systems (MAP1: 2% O2, 5% CO2, 93% N2 and MAP2: 3% O2, 7% CO2, 90% N2) to fresh-shelled ready-to-eat bamboo sprouts and compare these packaging systems with vacuum packaging during storage for 28 days at 4 °C using heat-sealable polyamide and polyethylene (PA/PE) trays. Several chemical-physical parameters (moisture content, water activity, pH, headspace composition, and firmness) were monitored, as well as CIELab colorimetric parameters and microbial growth. The quantification of selected organic acids was performed via UHPLC. Mathematical kinetic models were applied to study the evolution of total phenol (TPC), flavonoid (TFC), and carotenoid content (TCC) during storage. The evolution of antioxidant potential investigated by ABTS, DPPH, and β-carotene bleaching tests was also assessed. Results showed that at the end of the storage period, significant variations in the colorimetric parameters are detectable between the sprouts apical portion and the basal one, regardless of both applied MAPs. A linear reduction in both DPPH and ABTS radical scavenging activity was evidenced during storage, regardless of the type of packaging applied. In DPPH test samples packaged in MAP after 28 days of storage, they retain good antioxidant activity, whereas in vacuum, this activity is reduced by 50% compared to the initial value (IC50 values from 24.77 to 32.74 μg/mL and from 24.77 to 71.12 μg/mL for MAP2 and vacuum, respectively).

Grape Pomace Rich-Phenolics and Anthocyanins Extract: Production by Pressurized Liquid Extraction in Intermittent Process and Encapsulation by Spray-Drying

A considerable number of grape pomaces are generated annually. It represents a rich source of bioactive compounds, such as phenolic compounds and anthocyanins. Pressurized liquid extraction (PLE) has emerged as a green technology for recovering bioactive compounds from vegetal matrixes. In our study, PLE parameters (temperature, number of cycles, and rinse volume) have been studied to produce grape pomace extracts with high bioactive content using an experimental design. The experimental data obtained were adjusted to linear and quadratic models. The first-order model was better in predicting anthocyanins contents (TA, R2 = 0.94), whereas the second-order model was predictive for total phenolic compounds (TPC, R2 = 0.96). The main process parameter for the recovery of bioactive compounds was temperature, and the results showed opposing behaviors concerning TPC and TA, as it is difficult to optimize conditions for both. The extract containing the higher concentration of TPC (97.4 ± 1.1 mg GAE/g, d.b.) was encapsulated by spray-drying using maltodextrin as wall material. Particles presented with a spherical shape (~7.73 ± 0.95 μm) with a recovery yield of 79%. The results demonstrated that extraction followed by encapsulation of grape pomace extract is a good strategy to simplify future applications, whether for food, cosmetics or pharmaceutical fields.

Physicochemical, Technological and Functional Properties of Upcycled Vegetable Waste Ingredients as Affected by Processing and Storage

Vegetable wastes are generated during harvesting, processing, and distribution, which implies a wastage of nutrients and evidence inefficiencies in present food systems. Vegetable residues are rich in bioactive compounds, for which their valorisation and reintroduction into the food chain are crucial towards circular economy and food systems sustainability. In this work, upcycled powdered ingredients were obtained from vegetables wastes (carrot, white cabbage, celery, and leek) through a disruption, dehydration and milling process. Disruption pre-treatment at different intensities was followed by freeze-drying or hot-air drying (60 and 70 °C), and final milling to produce fine powders. Powdered products were characterized in terms of physicochemical, antioxidant and technological properties (water and oil interaction), after processing and during four months of storage. Antioxidant properties were generally favoured by hot-air drying, particularly at 70 °C, attributed to new compounds formation combined to less exposure time to drying conditions. The powders showed good water interaction properties, especially freeze-dried ones. Storage had a negative impact on the quality of powders: moisture increased, antioxidant compounds generally diminished, and colour changes were evidenced. Upcycled vegetable waste powders are proposed as ingredients to fortify foods, both processing and storage conditions having an impact on their properties.

Physicochemical and bioactive constituents, microbial counts, and color components of spray-dried Syzygium cumini L. pulp powder stored in different packaging materials under two controlled environmental conditions

Currently, the demand for functional food items that impart health benefits has been rising. Blackberry (Syzygium cumini L.) fruit has high anthocyanin content and other functional attributes. However, this seasonal fruit is highly perishable, and a large proportion of it goes unharvested and wasted worldwide. Spray drying of the fruit pulp can impart improved shelf life, ensuring long-term availability for consumers to exploit its health benefits. The storage quality varies according to the type of packaging material and the storage environment. Therefore, in this study, the shelf life span of the spray-dried Syzygium cumini L. pulp powder (SSCPP) was investigated during 6 months of storage under three types of packaging materials (i.e., polystyrene, metalized polyester, and 4-ply laminates) in a low-temperature environmental (LTE) and at ambient environmental conditions. The physicochemical stability of bioactive principles (TPC and TAC), microbial counts, and color components were analyzed at 0, 2, 4, and 6 months of storage. There was a significant gradual loss of dispersibility and solubility with an increase in flowability, bulk density, and wettability during the entire storage period for all three packaging materials. The TSS, pH, TPC, TAC, and microbial counts decreased in the SSCPP both at ambient and LTE conditions during the study. Among all the packaging materials, the 4-ply laminate was found to be the most appropriate and safe for storage of spray-dried SCPP at LTE conditions.

Tropical Red Fruit Blend Foam Mat Drying: Effect of Combination of Additives and Drying Temperatures

Foam mat drying is a widely used technique for liquid products because it has a number of advantages; however, for an efficient process, the choice of additives and temperatures is extremely important. The objective of this study was to evaluate the effect of additives and drying temperatures on the powders obtained from the blend of tropical red fruits, such as acerola, guava, and pitanga. The foam formulations were prepared by mixing the pulps of the three fruits in equal proportions (1:1:1), all added with 6% albumin and 1% stabilizing agent: E1, gum Arabic; E2, guar gum; E3, gelatin. The combinations were subjected to beating, and subsequently, they were dried in an oven with forced air circulation at four temperatures (50 to 80 °C), with a mat thickness of 0.5 cm. The obtained powders showed low levels of water and water activity and high levels of bioactive compounds, colors with a predominance of yellow, intermediate cohesiveness, poor fluidity, and solubility above 50%. The best temperature for obtaining the powders was 60 °C. The formulation that produced the best results for the production of the tropical red fruit blend powder was the combination of albumin and gelatin.

Influence of foam mat drying on the nutritional and technological potential of fruits - a review

The consumption of fruits and vegetables is strongly encouraged in the nutritional recommendations presented in national and international guidelines, which strongly advise the intake of these elements as part of a healthy diet. However, this type of food matrix has a low post-harvest durability, making it necessary to apply techniques that extend its shelf life. Among the methods that can be applied, drying acts as a unitary operation of wide use, presenting low operational cost, ease of handling and wide variation of procedural techniques. However, it still remains a methodology seen as "critical" in the food sector, especially when the maximum focus of efforts is to obtain a material of high quality, nutritional and sensorial. In this context, foam layer drying has gained recognition as an effective and low-cost technique, where foam porosity and higher surface area-volume ratio provide high heat and mass transfer rates, reducing process time and improving the physical-chemical quality of the final product. We provide information capable of elucidating that drying requires a large amount of energy for the operation, and that many studies are still needed in order to optimize the process and guarantee the economic, nutritional and functional viability of the final product.

Characterization of entrapment behavior of polyphenols in nanostructured lipid carriers and its effect on their antioxidative activity

Polyphenols are widely used as antioxidant agents to protect human health. Resveratrol, kaempferol, and quercetin have been reported to have potent antioxidant activity; however, these compounds have many problems related to their practical application, such as instability and insolubility. Thus, a nanostructured lipid carrier (NLC) was utilized as a drug delivery system (DDS) to overcome these limitations. This study investigated the particle stability, drug loading performance, and antioxidant activity of polyphenols-incorporated NLCs. The particle size and distribution were suitable for DDS applications, and all the samples demonstrated good stability after 2 months of storage. Based on Raman spectroscopy analysis, polyphenols were successfully encapsulated in NLCs. Quantitative high-performance liquid chromatography analysis indicated that NLCs could load resveratrol more than kaempferol and quercetin. In addition, NLCs have successfully improved all the antioxidant activity per unit concentration of polyphenol (specific antioxidant activity) compared to the free polyphenols. Quercetin-incorporated NLCs showed the highest specific antioxidant activity. This result is the opposite of entrapment efficiency and actual antioxidant activity, most likely influenced by the location of entrapped polyphenol molecules. As it was performed, NLCs are highly recommended to be applied as an antioxidant delivery system.

Effects of Cryoconcentrated Blueberry Juice as Functional Ingredient for Preparation of Commercial Confectionary Hydrogels

Hydrogels can absorb and/or retain components in the interstitial spaces due to the 3D cross-linked polymer network, and thus, these matrices can be used in different engineering applications. This study focuses on the physicochemical and textural properties, as well as bioactive compounds and their antioxidant activity stability of commercial hydrogels fortified with cryoconcentrated blueberry juice (CBJ) stored for 35 days. CBJ was added to commercial hydrogels (gelatin gel (GG), aerated gelatin gel (AGG), gummy (GM), and aerated gummy (AGM)). The samples showed a total polyphenol, anthocyanin, and flavonoid content ranging from 230 to 250 mg GAE/100 g, 3.5 to 3.9 mg C3G/100 g, and 120 to 136 mg CEQ/100 g, respectively, and GG and GM showed the lowest bioactive component degradation rate, while AGM presented the highest degradation. GG and GM samples could be stored for up to 21 days without significant changes, while the results indicated ≈15 days for the AGG and AGM samples. Thereby, CBJ offers enormous possibilities to be used as a functional ingredient due to the high nutritional values, and it allows enriching different hydrogel samples, and in turn, the structures of hydrogels protected components during in vitro digestion, enhancing the bioaccessibility after the digestion process.

Foaming characteristics and impact of ethanol pretreatment in drying behavior and physical characteristics for avocado pulp powder obtained by foam mat drying

The objective of this study was to optimize the production of powdered avocado using foam mat drying. In order to achieve this, the effect of Emustab^® (4, 6, and 8% w/w), goat's milk (10, 15, and 20% w/w), and whipping time (15, 20, and 25 min) on the foam physical properties of avocado pulp were evaluated. In addition, the influence of ethanol pretreatment on the drying kinetics, thermodynamic properties, and physicochemical characteristics of the powders was also assessed. An experimental design 2³ with three central points was used in this study and optimized foam conditions were dried at 50, 60, and 70°C, with a fixed air speed of 1.5 m/s. Empirical and diffusive models (boundary conditions of the third type) were adjusted to the experimental data to describe the drying kinetics and to determine the process activation energy and thermodynamic properties. The final products were characterized regarding their physical properties. Optimized foam mat drying conditions were achieved when avocado pulp was whipped for 15 min and 8% of Emustab^® and 20% of powdered goat milk were used as foaming agents. The use of an ethanol pretreatment and higher drying temperature (70°C) resulted in higher drying rate (1.6 × 10² /min) and shorter processing time (270 min). The ethanol pretreatment reduced the activation energy and Biot number and led to more uniform moisture distribution. The physical properties, such as water content, water activity, bulk, and tapped densities decreased with an increase in drying temperature and pretreatment with ethanol, whereas water absorption capacity increased. PRACTICAL APPLICATION: In this work, new information about the drying kinetics and mass transfer of the foam mat avocado pulp using ethanol as pretreatment is obtained. The results will contribute to the optimization production avocado foaming and powder. Ethanol pretreatment can represent an alternative to minimize the negative impacts on drying process and can be surely suggested as an industrial application.

Inactivation of Escherichia coli O157:H7 in apple juice via induced electric field (IEF) and its bactericidal mechanism

Non-conventional heating technology based on electric fields can be utilized to process liquid foods. In this study, the induced electric field (IEF) was investigated to clarify its inactivation mechanism on E.coli. Staining results show that inactivation of E.coli by IEF can be attributed to the reversible destruction of the cell membrane, followed by the denaturation of intracellular enzymes, and finally the irreversible rupture of the cell membrane. The increased levels of extracellular proteins and nucleic acids were also observed. IEF treatment at 400 Hz and 800 V (or 53 V/cm) results in a reduction of 4.5 log CFU·mL^-1 in the number of E.coli. Storage life analysis shows that IEF treatment can improve the stability of apple juice and the content of bioactive components. Thus, IEF is a potential technique for liquid food processing.

Storage stability of 5-caffeoylquinic acid in powdered cocona pulp microencapsulated with hydrolyzed collagen and maltodextrin blend

The encapsulation efficiency of spray-dried cocona pulp encapsulated with a blend of maltodextrin (MD) and hydrolyzed collagen (HC) (CP-ENC) and the stability, color parameters, antioxidant capacity (FRAP and ABTS), and 5-caffeoylquinic acid content were evaluated through 120 days of storage, at every 15 days, at 25 and 35 °C. The results of CP-ENC were compared to those of pure freeze-dried cocona pulp (CP-nENC). The sorption isotherms and glass transition temperatures (Tg) were determined in order to evaluate the stability of the cocona powder. The GAB model fitted well the experimental data for moisture sorption of samples. The high Tg for CP-ENC (132.02 °C) was attributed to the high molecular weight of encapsulating agents. The encapsulation efficiency and color parameters for CP-ENC kept constant values for 120 days. A loss of 30% in the antioxidant capacity occurred on day 75 for CP-ENC. The values of retention of 5-CQA for CP-ENC (83% and 68% when stored at 25 and 35 °C, respectively) were greater than those observed for CP-nENC. At 25 °C, stored CP-ENC had a higher retention and a longer half-life of 5-CQA (14.4 months) than CP-nENC. The results suggest that it is suitable to microencapsulate cocona pulp with MD and HC to improve protection of antioxidant compounds, throughout storage at 25 °C.

Jambul (Syzygium cumini) Pulp Extract Enhances Viability, Motility, and In Vitro Fertilizability of Cryopreserved Bovine Semen

To study the ameliorative capacity of Syzygium cumini fruit Pulp Extract (SPE) on cryopreserved bovine semen, three ejaculates each of three fertile bulls (total nine samples) were collected. Each sample was mixed with semen dilution medium in 1:2 ratios, centrifuged, and 50% of the supernatant was discarded. The remaining sample was mixed with semen cryopreservation extender (SCE) in 1:4 ratios. Three aliquots (0.3 mL) of each extended semen sample were further diluted with (1) 0.7 mL SCE (SCE group), (2) 0.7 mL SCE containing SPE equivalent to 7 ppm total antioxidants (SPE7 group), and (3) 0.7 mL SCE equivalent to 14 ppm antioxidants (SPE14 group). For each aliquot, semen quality was analyzed in situ as well as after cryopreservation. Results show significant improvement in sperm membrane integrity, motility, and fertilizability in SPE7 (63.5% ± 2.04%, 56.22% ± 1.7%, 51.1%, respectively) and SPE14 (68% ± 1.12%, 63.67% ± 1.06%, 57.7%, respectively) than the SCE group (62.33% ± 1.22%, 54.9% ± 1.34%, 48.8%, respectively). Similarly, significant improvement in the mean percent number of progressively motile sperm at the expense of the mean percent twitching, shaking, and whirling spermatozoa, both before and after cryopreservation, were observed in SPE7 (72 ± 1.06, 61.2 ± 1.2) and SPE14 (78.89 ± 1.12, 67 ± 1.32) groups to that of the SCE (59.6 ± 0.97, 52.3 ± 3.5). In addition, the mean percent of progressively motile spermatozoa showing 20 μm/s or above velocity, before and after cryopreservation, were significantly higher in SPE7 (58.9 ± 4.7, 43.6 ± 1.5) and SPE14 (66.9 ± 0.8, 51.3 ± 0.8) groups than that of the SCE (42.3 ± 3.1, 30 ± 2.4). These findings indicate that SPE can significantly improve various quality parameters of the cryopreserved bovine semen.

Anthocyanins: From the Field to the Antioxidants in the Body

Anthocyanins are biologically active water-soluble plant pigments that are responsible for blue, purple, and red colors in various plant parts-especially in fruits and blooms. Anthocyanins have attracted attention as natural food colorants to be used in yogurts, juices, marmalades, and bakery products. Numerous studies have also indicated the beneficial health effects of anthocyanins and their metabolites on human or animal organisms, including free-radical scavenging and antioxidant activity. Thus, our aim was to review the current knowledge about anthocyanin occurrence in plants, their stability during processing, and also the bioavailability and protective effects related to the antioxidant activity of anthocyanins in human and animal brains, hearts, livers, and kidneys.