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

Extraction techniques in food industry: Insights into process parameters and their optimization

This review presents critical evaluation of the key parameters that affect the extraction of targeted components, giving due consideration to safety and environmental aspects. The crucial aspects of the extraction technologies along with protocols and process parameters for designing unit operations have been emphasized. The parameters like solvent usage, substrate type, concentration, particle size, temperature, quality and storage of extract as well as stability of extraction have been elaborately discussed. The process optimization using mathematical and computational modeling highlighting information and communication technologies have been given importance aiming for a green and sustainable industry level scaleup. The findings indicate that the extraction processes vary significantly depending on the category of food and its structure. There is no single extraction method or universal set of process conditions identified for extracting all value-added products from respective sources. A comprehensive understanding of process parameters and their optimization as well as synergistic combination of multiple extraction processes can aid in enhancement of the overall extraction efficiency. Future efforts must be directed toward the design of integrated unit operations that cause minimal harm to the environment along with investigations on economic feasibility to ensure sustainable extraction systems.

By-Products Revalorization with Non-Thermal Treatments to Enhance Phytochemical Compounds of Fruit and Vegetables Derived Products: A Review

The aim of this review is to provide comprehensive information about non-thermal technologies applied in fruit and vegetables (F&V) by-products to enhance their phytochemicals and to obtain pectin. Moreover, the potential use of such compounds for food supplementation will also be of particular interest as a relevant and sustainable strategy to increase functional properties. The thermal instability of bioactive compounds, which induces a reduction of the content, has led to research and development during recent decades of non-thermal innovative technologies to preserve such nutraceuticals. Therefore, ultrasounds, light stresses, enzyme assisted treatment, fermentation, electro-technologies and high pressure, among others, have been developed and improved. Scientific evidence of F&V by-products application in food, pharmacologic and cosmetic products, and packaging materials were also found. Among food applications, it could be mentioned as enriched minimally processed fruits, beverages and purees fortification, healthier and "clean label" bakery and confectionary products, intelligent food packaging, and edible coatings. Future investigations should be focused on the optimization of 'green' non-thermal and sustainable-technologies on the F&V by-products' key compounds for the full-utilization of raw material in the food industry.

Morphological and Rheological Guided Design for the Microencapsulation Process of Lactobacillus paracasei CBA L74 in Calcium Alginate Microspheres

The intestinal microbiota is a real ecosystem composed of several bacterial species and a very huge amount of strains that through their metabolic activities play a crucial role in the development and performance of the immune system and other functions. Microbiota modulation by probiotics establishes a new era into the pharmaceutical and healthcare market. Probiotics play, in fact, an important role in helping and sustaining human health, but in order to produce benefits, their viability must be preserved throughout the production process up to consumption, and in addition, their bioactivity required to be safeguarded while passing through the gastrointestinal tract. In this frame, encouraging results come from encapsulation strategies that have proven to be very promising in protecting bacteria and their viability. However, specific effort has to be dedicated to the design optimization of the encapsulation process and, in particular, to the processing parameters that affect capsules microstructure. Herein, focusing on calcium alginate microspheres, after a preliminary selection of their processing conditions based on size distribution, we implemented a micro-rheological analysis, by using the multiple-particle tracking technique, to correlate the inner microstructure to the selected process conditions and to the viability of the Lactobacillus paracasei CBA L74. It was assessed that the explored levels of cross-linking, although changing the microorganism constriction, did not affect its viability. The obtained results confirm how this technology is a promising and a valid strategy to protect the microorganism viability and ensure its stability during the production process.

Grape Pomace Valorization: A Systematic Review and Meta-Analysis

This systematic review aimed to collect data and analyze the possible use of grape pomace, a winemaking industry byproduct, in the production of fortified foods. The English articles found in Web of Science, Scopus, and Google Scholar, from January 2006 until May 2020, were used for the conduction of overview tables and meta-analysis. The systematic review emphasized the two main issues concerning grape pomace application to other food products: (i) grape pomace contains high amounts of health promoting compounds; and (ii) the use of grape pomace is influencing the waste management. The grape pomace has been used in the fortification of plant origin food, meat, fish, and dairy products, mainly due to higher polyphenols and dietary fiber contents. The fortification was declared as successful in all studied food types. The change of color, caused by polyphenolic compounds, was mainly observed as an adverse effect of the fortification. Higher levels of fortification also caused notable undesirable changes in texture. The most valuable influence of the grape pomace addition according to included papers and meta-analysis is certainly a higher nutritional quality and oxidative stability of fortified products, reflected as higher polyphenol and total dietary fiber content.

Use of Grape Pomace Phenolics to Counteract Endogenous and Exogenous Formation of Advanced Glycation End-Products

The increase in consumption of "ultra-processed" foods has raised attention because of the possible adverse effects deriving from the Maillard reaction leading to the formation of toxic advanced glycation end-products (AGEs) during food processing. Additionally, the increasing trend and consumption of sugar-added foods and sweetened beverages is related to the endogenous formation of the same toxic compounds. However, ultra-processing in the context of food technology can bring challenges as well as a wealth of opportunities. Indeed, re-processing of grape pomace, a by-product of winemaking, can yield phenolic-rich fractions that efficiently counteract the effects of AGEs. In this review, the process of endogenous and exogenous AGE formation is illustrated. Then, the ability of grape phenolics to act as inhibitors of AGE formation is presented, including the efficacy ranking of various individual compounds measured in vitro and the outcome of in vivo double-blinded randomized crossover trials designed to prove the efficacy of grape phenolics as inhibitors of protein carbonylation. Finally, a survey of model functional foods added with grape phenolics, either to lower the dietary load of AGEs or to deliver antiglycation agents in vivo is listed in order to highlight the opportunity to develop safe and tailor-made "anti-AGEs" food applications.

In vitro digestion of meat- and cereal-based food matrix enriched with grape extracts: How are polyphenol composition, bioaccessibility and antioxidant activity affected?

The aim of this study was to evaluate the effect of enriching a complex food matrix (FM) with grape extracts on polyphenol content, composition, bioaccessibility and antioxidant activity during digestion. The grape extracts and FM were separately tested under the same conditions as controls. The FM by itself contains a significant amount of phenolic acids and flavonols, influencing the final recovery of polyphenols from grape extracts. The FM significantly increased the total recovery of polyphenols after digestion of grape seed extracts compared to those digested without the FM; however, a low recovery of proantocyanidins and total flavonoids was observed. Digestive fluids and FM compounds significantly increased the total polyphenol content of grape digests and significantly contributed to their ABTS⁺ scavenging activity and ferrous-ion-chelating capacity. The present study suggested that enrichment of meat- and cereal-based products with grape polyphenol extracts could be a good strategy to formulate a healthier diet.

Effects of in vitro gastrointestinal digestion on phenolic compounds and antioxidant activity of different white winemaking byproducts extracts

The effect of in vitro gastrointestinal digestion on phenolic composition and antioxidant activity of different white winemaking byproducts extracts (grape pomace and its parts: seeds, skins and stems) was evaluated. Fourteen individual phenolic compounds were evaluated by UHPLC. The antioxidant activity was measured by DPPH and ORAC assays. Differences on phenolic profile and antioxidant activity were observed depending on the digestion phase, the type of byproduct, the phenolic group and the antioxidant activity assay. In general, digestion had a reducing effect on TPC and antioxidant activity; however, ORAC values of seed and stem extracts increased after digestion and some recovery indexes of the phenolic groups were very high. Results indicate that extracts from white winemaking byproducts are a reliable source of bioaccessible antioxidant compounds, which could be used as functional food ingredients.

Effect of Drying on the Phenolic Content and Antioxidant Activity of Red Grape Pomace

Winemaking by-products are considered to be a rich source of bioactive compounds. Grape pomace is susceptible to microbial degradation due to the degree of residual moisture, so the drying of this pomace for conservation is considered to be an essential first step. Previous studies concerning the way in which drying affects winery by-products have produced contradictory results. In this study, a new methodology for drying grape pomace in a climatic chamber has been evaluated. Five red grape pomace varieties were dried in a climatic chamber at 40 °C and 10% relative humidity and the phenolic content and antioxidant activity of the dried and wet pomace samples were compared. The results indicate that this drying process is both feasible and beneficial because significant increases in the extractability of phenolic compounds and antioxidant activity were achieved.

Effect of particle size on phytochemical composition and antioxidant properties of two persimmon flours from Diospyros kaki Thunb. vars. 'Rojo Brillante' and 'Triumph' co-products

BACKGROUND

This contribution studies the influence of the particle size of persimmon flours (from two cultivars, 'Rojo Brillante' and 'Triumph') on their primary (sugars and organic acids) and secondary (polyphenols, flavonoids and carotenoids) metabolite content, and also on their antioxidant activity, to assess whether these flours could find applications in the food industry as a potential functional ingredient.

RESULTS

The main sugars were fructose and glucose and the principal organic acid was malic acid. The highest content of total phenols, flavonoids and carotenoids was found in flour fractions from cv. 'Rojo Brillante'. The phenol profile determined by HPLC identified six phenolic compounds in both persimmon flours, the most abundant being gallic acid. The greatest ABTS and DPPH radical scavenging capacity and ferric reducing power were found in flour fractions from cv. 'Rojo Brillante'. Although the influence of particle size on all these properties was not always evident, in general, the higher bioactive compound content and antioxidant capacity were in the finest particles.

CONCLUSION

Co-products from cvs. 'Rojo Brillante' and 'Triumph' persimmon juice extraction can be processed to obtain flours rich in sugars, organic acids and bioactive compounds, suggesting their possible use as a functional ingredient (with antioxidant properties) in different food products. © 2017 Society of Chemical Industry.

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.

Quality characteristics of wheat flour dough and bread containing grape pomace flour

Wheat bread was enriched with 6%, 10% and 15% dried and milled grape pomace flour from two grape cultivars: ‘Merlot’ and ‘Zelen’. Rheological, textural, sensory and antioxidant properties of the enriched dough and bread were evaluated, and compared to control samples. Grape cultivar had significant impact on the rheological characteristics of the dough, and on the sensory and antioxidant properties of the final bread. Development time and dough stability were longer when ‘Merlot’ grape pomace flour was added compared to ‘Zelen’ grape pomace flour and the control. Grape pomace flour addition affected bread volume, firmness, crumb and crust colour, and odour and taste intensity. Moreover, grape pomace flour addition resulted in a stickier and less springy crumb texture, and some negative sensorial properties, such as increased intensity of aftertaste and sand feeling in the mouth. The phenolic content and antioxidant activity of bread were positively correlated with grape pomace flour addition ( r = 0.987, p = 0.01 and r = 0.941, p = 0.01 between phenolic content and ferric reducing antioxidant power and phenolic content and 2,2-diphenyl-1-picrylhydrazyl, respectively). The highest total phenolic contents were 5.92 mg gallic acid equivalents (GAE)/g dw for ‘Merlot’ and 3.65 mg gallic acid equivalents /g dw for ‘Zelen’, which were seen for the bread prepared with the highest grape pomace flour addition (15%). The highest antioxidant activity determined by the 2,2-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant power assays were seen for the bread prepared with the highest ‘Merlot’ grape pomace flour addition (15%). Dough characteristic and sensory profile are strongly influenced by cultivar of grape pomace flour. Based on results of sensory profiling, the variety ‘Zelen’ is suggested for use.

Techno-functional properties of tomato puree fortified with anthocyanin pigments

This study investigates the effects of tomato puree fortification with several anthocyanin-rich food colorants on bioactive compound content (phenolics, isoprenoids), antioxidant capacity, in vitro biological activities and consumer acceptance. Tomato puree (tp) was added with different anthocyanin extracts from black carrot (Anthocarrot), grape fruit skins (Enocolor), elderberry fruits (Elderberry) or mahaleb cherry fruits (Mahaleb), thus obtaining a 'functional tomato puree' (ftp). The consumer acceptance (colour, flavor, taste, visual appearance) was at high level, except for Mahaleb-added ftp. Compared to the control (tp), the addition of colouring extracts increased significantly the total phenolic content, before pasteurization, in addition to the expected anthocyanin content. However, after pasteurization, mostly Anthocarrot-ftp preserved an increased phenolic (+53%) content, as well as a higher antioxidant capacity (50%), more than the other added-extracts. Consistently, against tp, Anthocarrot-ftp exhibited an increased anti-inflammatory capacity as showed by the reduced expression of vascular cell adhesion molecule (VCAM)-1 in human cultured endothelial cells, under inflammatory conditions.

Grape skin phenolics as inhibitors of mammalian α-glucosidase and α-amylase--effect of food matrix and processing on efficacy

Type-2 diabetes is continuously increasing worldwide. Hence, there is a need to develop functional foods that efficiently alleviate damage due to hyperglycaemia complications while meeting the criteria for a sustainable food processing technology. Inhibition of mammalian α-amylase and α-glucosidase was studied for white grape skin samples recovered from wineries and found to be higher than that of the drug acarbose. In white grape skins, quercetin and kaempferol derivatives, analysed by UPLC-DAD-MS, and the oligomeric series of catechin/epicatechin units and their gallic acid ester derivatives up to nonamers, analysed by MALDI-TOF-MS were identified. White grape skin was then used for enrichment of a tomato puree (3%) and a flat bread (10%). White grape skin phenolics were found in the extract obtained from the enriched foods, except for the higher mass proanthocyanidin oligomers, mainly due to their binding to the matrix and to a lesser extent to heat degradation. Proanthocyanidin solubility was lower in bread, most probably due to formation of binary proanthocyanin/protein complexes, than in tomato puree where possible formation of ternary proanthocyanidin/protein/pectin complexes can enhance solubility. Enzyme inhibition by the enriched foods was significantly higher than for unfortified foods. Hence, this in vitro approach provided a platform to study potential dietary agents to alleviate hyperglycaemia damage and suggested that grape skin phenolics could be effective even if the higher mass proanthocyanidins are bound to the food matrix.

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.

A sensory- and consumer-based approach to optimize cheese enrichment with grape skin powders

The present study aimed to present a sensory- and consumer-based approach to optimize cheese enrichment with grape skin powders (GSP). The combined sensory evaluation approach, involving a descriptive and an affective test, respectively, was applied to evaluate the effect of the addition of grape skin powders from 2 grape varieties (Barbera and Chardonnay) at different levels [0.8, 1.6, and 2.4%; weight (wt) powder/wt curd] on the sensory properties and consumer acceptability of innovative soft cow milk cheeses. The experimental plan envisaged 7 products, 6 fortified prototypes (at rates of Barbera and Chardonnay of 0.8, 1.6, and 2.4%) and a control sample, with 1 wk of ripening. By means of a free choice profile, 21 cheese experts described the sensory properties of prototypes. A central location test with 90 consumers was subsequently conducted to assess the acceptability of samples. The GSP enrichment strongly affected the sensory properties of innovative products, mainly in terms of appearance and texture. Fortified samples were typically described with a marbling aspect (violet or brown as function of the grape variety) and with an increased granularity, sourness, saltiness, and astringency. The fortification also contributed certain vegetable sensations perceived at low intensity (grassy, cereal, nuts), and some potential negative sensations (earthy, animal, winy, varnish). The white color, the homogeneous dough, the compact and elastic texture, and the presence of lactic flavors resulted the positive drivers of preference. On the contrary, the marbling aspect, granularity, sandiness, sourness, saltiness, and astringency negatively affected the cheese acceptability for amounts of powder, exceeding 0.8 and 1.6% for the Barbera and Chardonnay prototypes, respectively. Therefore, the amount of powder resulted a critical parameter for liking of fortified cheeses and a discriminant between the 2 varieties. Reducing the GSP particle size and improving the GSP dispersion in the curd would reduce the effect of powder addition on sensory properties, thereby encouraging the use of these polyphenol-based fortifiers in cheeses. The proposed approach allowed the identification of sensory properties critical for product acceptability by consumers, thus helping the optimization of both fortifier characteristics and new cheese production and composition.

Physicochemical and nutritional qualities of grape pomace powder-fortified semi-hard cheeses

Powders obtained from three grape pomaces (Barbera, Chardonnay before distillation, Chardonnay after distillation) were added at two concentration levels (0.8 and 1.6 % w/w) into semi-hard and hard cheeses (Italian Toma-like and Cheddar, respectively) to increase their polyphenol content. Effects on physicochemical characteristics, total phenolic content (TPC), radical scavenging activity (RSA), proteolysis, organic acids content, starter and non-starter bacteria were evaluated during ripening. The amount and the type of powder used did not significantly affect the physicochemical parameters of cheese with the exception of pH their values. Italian Toma-like and Cheddar cheeses fortified with Chardonnay after distillation powder showed at the end of ripening (30 days and 120 days respectively) the highest TPC and RSA values. Proteolysis and microbial counts did not show statistically significant differences between fortified and control cheeses. This study demonstrated that grape pomace powder can be a functional ingredient to increase TPC and RSA in consumers' diets and the addition of this by-product to cheese is an environmentally friendly way to manage winemaking wastes.

The 9-point hedonic scale and hedonic ranking in food science: some reappraisals and alternatives

The 9-point hedonic scale has been used routinely in food science, the same way for 60 years. Now, with advances in technology, data from the scale are being used for more and more complex programs for statistical analysis and modeling. Accordingly, it is worth reconsidering the presentation protocols and the analyses associated with the scale, as well as some alternatives. How the brain generates numbers and the types of numbers it generates has relevance for the choice of measurement protocols. There are alternatives to the generally used serial monadic protocol, which can be more suitable. Traditionally, the 'words' on the 9-point hedonic scale are reassigned as 'numbers', while other '9-point hedonic scales' are purely numerical; the two are not interchangeable. Parametric statistical analysis of scaling data is examined critically and alternatives discussed. The potential of a promising alternative to scaling itself, simple ranking with a hedonic R-Index signal detection analysis, is explored in comparison with the 9-point hedonic scale.

Comparative study of the enological potential of different winemaking byproducts: implications in the antioxidant activity and color expression of red wine anthocyanins in a model solution

Different white winemaking byproducts (pomace, skins, seeds, and stems) were compared as natural sources of phenolic compounds having biological and sensory properties of enological interest. Antioxidant and copigmentation effects of these byproducts were studied in a wine-like model solution. RRLC-DAD was used to establish differences in the phenolic composition, and the ABTS method was used to compare the antioxidant activities. Spectrophotometric and colorimetric analyses were performed to assess the magnitude of copigmentation and the changes induced in the color expression of red wine anthocyanins. Antioxidant and copigmentation properties significantly varied depending on the type of byproduct, which was related to their qualitative and quantitative phenolic composition. Seeds and pomace showed the highest antioxidant potential, whereas skins and pomace led to the strongest and visually perceptible color effects on red wine anthocyanins by multiple copigmentation (darker, more saturated, and vivid bluish colors). Results open the possibility of technological applications for the wine industry based on reusing winemaking byproducts to improve the biological value and color characteristics of red wines.