Effect of grape dietary fibre on the storage stability of innovative functional seafood products made from farmed meagre (Argyrosomus regius)

Comparison of Antibacterial and Antioxidant Properties of Red (cv. Negramaro) and White (cv. Fiano) Skin Pomace Extracts

Wine pomace has attracted the attention of the food industry, due to its high content in bioactive compounds, and its multiple healthy activities. In this work, whole and separated skin pomaces from fermented (red) and un-fermented (white) grape by-products were characterized for their antioxidant and antimicrobial activities in order to exploit them as functional food ingredient. Antioxidant activity, measured by both ORAC and TEAC assays, was higher in whole than in skin pomace extracts. The characterization of phenolic composition in whole and skin pomace extracts confirmed the peculiarity of some compounds such as anthocyanins (107.84 + 10.3 mg/g TP) in red skin pomace and a great amount of flavanols (80.73 + 4.04 mg/g TP) in white skin pomace. Whole and skin pomace extracts displayed the same antibacterial activity at 250 µg gallic acid equivalents (GAE)/mL. Red and white skin pomace extracts showed a Minimum Inhibitory Concentration (MIC) of 31.25-62.5 GAE/mL against Staphylococcus aureus and Enterococcus faecalis. Pseudomonas spp. were more sensitive to red skin pomace extracts rather than white skin pomace extracts. Given these results, both red and white pomace extracts could be exploited for future application in food, pharmaceutical and cosmetic industry.

Stability of refrigerated traditional and liquid smoked catfish (Sciades herzbergii) sausages

Catfish (Sciades herzbergii) are widely captured in Brazilian Northeast but have low commercial value. The processing of catfish into an innovative product with longer shelf life can add value to the fish and improve sustainability. The objective of this study was to investigate the stability during 60 days of refrigerated storage smoked sausages produced by two different smoking processes (traditional smoking [TS] and liquid smoking [LS]). The smoking processes affected fat and ash contents, hardness, and CIE (Commission Internationale de L'Eclairage) color (L* and b* values). TS sausages had higher fat content and yellowness (b* value). LS sausages had higher ash content (15 days of storage) and lightness (L* value). The sausage's hardness was higher at 45 days of storage for TS and at 60 days for LS sausages. During refrigerated storage, there were decreases in crude protein (309.12-263.49 g/kg, 1-30 days, respectively), water holding capacity (89.77%-87.39%, 1-45 days, respectively), and redness (a* value) (10.35-6.09, 1-30 days, respectively), and increases in hardness (TS = 31.92-55.92 N, 1-45 days, respectively; LS = 32.88-61.18N, 160 days, respectively) and TBARS values (1.56-2.38 mg malonaldehyde/kg, 1-60 days, respectively). The microbial quality was kept within Brazilian legislation limits. Therefore, liquid smoked catfish sausage consists of a convenient innovative product, which is easier to process and control and provides a product with good physicochemical, microbial, and biochemical characteristics for up to 60 days of storage. PRACTICAL APPLICATION: Catfish, a low commercial value fish (by catch from shrimp operations), can be processed into a high value smoked sausage. Liquid smoking was easier to process, environment friendly, and easier to control compared to traditional smoking. It provided a nutritional, easy to prepare at home, and microbial safe product with a shelf life under refrigeration up to 60 days. It can be successfully used to warrant sustainability in the fish chain.

Non-Extractable Polyphenols from Food By-Products: Current Knowledge on Recovery, Characterisation, and Potential Applications

Non-extractable polyphenols (NEPs), or bound polyphenols, are a significant fraction of polyphenols that are retained in the extraction residues after conventional aqueous organic solvent extraction. They include both high molecular weight polymeric polyphenols and low molecular weight phenolics attached to macromolecules. Current knowledge proved that these bioactive compounds possess high antioxidant, antidiabetic, and other biological activities. Plant-based food by-products, such as peels, pomace, and seeds, possess high amount of NEPs. The recovery of these valuable compounds is considered an effective way to recycle food by-products and mitigate pollution, bad manufacturing practice, and economic loss caused by the residues management. The current challenge to valorise NEPs from plant-based by-products is to increase the extraction efficiency with proper techniques, choose appropriate characterising methods, and explore potential functions to use in some products. Based on this scenario, the present review aims to summarise the extraction procedure and technologies applied to recover NEPs from plant-based by-products. Furthermore, it also describes the main techniques used for the characterisation of NEPs and outlines their potential food, pharmaceutical, nutraceutical, and cosmetic applications.

The life and times of yeasts in traditional food fermentations

Yeasts are eukaryotic microorganisms which have a long history in the biotechnology of food production, as they have been used since centuries in bread-making or in the production of alcoholic beverages such as wines or beers. Relative to this importance, a lot of research has been devoted to the study of yeasts involved in making these important products. The role of yeasts in other fermentations in association with other microorganisms - mainly lactic acid bacteria - has been relatively less studied, and often it is not clear if yeasts occurring in such fermentations are contaminants with no role in the fermentation, spoilage microorganisms or whether they actually serve a technological or functional purpose. Some knowledge is available for yeasts used as starter cultures in fermented raw sausages or in the production of acid curd cheeses. This review aimed to summarize the current knowledge on the taxonomy, the presence and potential functional or technological roles of yeasts in traditional fermented plant, dairy, fish and meat fermentations.

Development of Semiliquid Ingredients from Grape Skins and Their Potential Impact on the Reducing Capacity of Model Functional Foods

Grape skins (GS), which can be considered as reusable coproducts of winemaking, were processed to develop semiliquid ingredients for functional foods, as an alternative to powdered GS, which needs high energy input for drying. Processing of semiliquid GS ingredients included blanching, dilution to obtain dispersions with 2% or 10% of dry solids, milling, homogenization, and pasteurization. The individual phenolic contents and in vitro ferric ion reducing capacity (FRAP) of semiliquid GS ingredients were compared with those of air-dried and freeze-dried GS. With respect to freeze-dried GS, the recovery of FRAP values was ~75% for both air-dried GS and 2% GS dispersion and 59% for 10% GS dispersion. The average particle size diameters of solids in semiliquid GS ingredients were similar to those observed in commercial apple skin products. Possible applications of GS semiliquid ingredients to increase the reducing capacity of food 10 times include formulation into beverages and ice-type desserts and use in bakery products.

Applications of Wine Pomace in the Food Industry: Approaches and Functions

Winemaking generates large amounts of wine pomace, also called grape pomace. This by-product has attracted the attention of food scientists and the food industry, due to its high content in nutrients and bioactive compounds. This review mainly focuses on the different published approaches to the use of wine pomace and its functions in the food industry. Traditionally, wine pomace has been used to obtain wine alcohol, food colorings, and grape seed oil. More recently, research has focused in the production of other value-added products, such as extracts of bioactive compounds, mainly phenols, recovery of tartaric acid, and the making of flours. The most common functions associated with wine pomace products are their use as antioxidants, followed by their use as fortifying, coloring, and antimicrobial agents. These products have mainly been applied to the preparation of meat and fish products and to, a lesser extent, cereal products.

Protective ability of phenolics from white grape vinification by-products against structural damage of bovine serum albumin induced by glycation

Grape skins recovered from white grape vinification processes were studied as possible anti-glycation agents. Total phenolics were characterised by the Folin Ciocalteu assay, proanthocyanidins by depolymerisation with n-butanol/HCl, flavonols by HPLC-DAD, reducing capacity by ferric ion reducing antioxidant power assay (FRAP) and anti-glycation activity by a bovine serum albumin (BSA)/fructose model system. Structural modifications of BSA were investigated by 2D isoelectric focusing sodium dodecyl sulfate polyacrylamide gel electrophoresis (IEF/SDS-PAGE) and fluorescence measurements. Both pI and Mr. of BSA were modified upon glycation reaction. These changes attributable to the involvement of free amino groups in Maillard-type reactions were inhibited by the white grape skin extracts. The anti-glycation activity ranged between 250 and 711mmol aminoguanidine Eq/kg. These results raise the interest in the potential health benefits of by-products of white grape vinification that could have a secondary use as an ingredient for new functional foods targeting wellbeing of diabetic and elderly people.

Use of winemaking by-products as an ingredient for tomato puree: the effect of particle size on product quality

Formulations of tomato puree with grape skin fibres (Chardonnay variety) having varying particle sizes were studied. The contents of flavonoids (by HPLC-DAD) and proanthocyanidins (n-butanol/HCl assay), reducing capacity (ferric ion reducing antioxidant power, FRAP) and anti-glycation activity by a bovine serum albumin (BSA)/fructose model system were analysed in vitro. A liking test was performed with consumers. Stabilization was carried out by either an intensive autoclave treatment or an optimised microwave-treatment achieving 6D-reduction of the target microorganism (Alicylobacillus acidoterrestris). In the fortified tomato purees, the solubility of proanthocyanidins decreased, but was partly restored by autoclave treatment, which also caused deglycosylation of flavonol glycosides. Microwave treatment did not show any effect on phenolics. The reducing capacity and ability to inhibit protein glycation greatly increased in the fortified purees. The particle sizes of solids in the formulations played a major role with respect to the consumers' liking, with the smallest fraction showing maximum ratings.