Antonietta Baiano

Recovery of Biomolecules from Food Wastes — A Review

Food wastes are produced by a variety of sources, ranging from agricultural operations to household consumption. About 38% occurs during food processing. At present, the European Union legislation encourages the exploitation of co-products. This valorisation can be achieved through the extraction of high-value components such as proteins, polysaccharides, fibres, flavour compounds, and phytochemicals, which can be re-used as nutritionally and pharmacologically functional ingredients. Extraction can proceed according to solid-liquid extraction, Soxhlet extraction, pressurized fluid extraction, supercritical fluid extraction, ultrasound-assisted extraction, microwave-assisted extraction, pulsed electric field extraction, and enzyme-assisted extraction. Nevertheless, these techniques cannot be used indiscriminately and their choice depends on the type of biomolecules and matrix, the scale processing (laboratory or industrial), the ratio between production costs and economic values of the compounds to be extracted. The vegetable wastes include trimmings, peelings, stems, seeds, shells, bran, residues remaining after extraction of oil, starch, sugar, and juice. The animal-derived wastes include wastes from bred animals, wastes from seafood, wastes from dairy processing. The recovered biomolecules and by-products can be used to produce functional foods or as adjuvants in food processing or in medicinal and pharmaceutical preparations. This work is an overview of the type and amounts of food wastes; food waste legislation; conventional and novel techniques suitable for extracting biomolecules; food, medicinal and pharmaceutical uses of the recovered biomolecules and by-products, and future trends in these areas.

Prevention of enzymatic browning in sliced potatoes by blanching in boiling saline solutions

The response surface methodology was applied to investigate the way in which variables, such as time of treatment, sodium or calcium chloride concentrations and lactic acid concentration, affect the blanching of potato slices in boiling solutions. Two 3 factor-5 level, second order central composite designs were developed to analyse the considered variables. Results showed that all the considered blanching treatments allowed polyphenoloxidase inactivation. With regard to colour, the use of calcium chloride, already at low concentrations, would seem better than the use of sodium chloride. Under the applied operative conditions, the best results were obtained with short times of treatment and low lactic acid concentrations.

Phenolic Content and Antioxidant Activity of Primitivo Wine: Comparison among Winemaking Technologies

The aim of this study was to assess the influence of 9 winemaking technologies (traditional, delestage, saignée, delayed punching-down, addition of grape seed tannins, addition of ellagic-skin-seed tannins, heating of must-wine, cryo-maceration, and prolonged maceration) on the phenolic content and antioxidant activity of Primitivo musts and wines. Three methods for the determination of the antioxidant activity were compared: DPPH, beta-carotene bleaching assay, and ABTS. Oenological parameters and composition of the phenolic fraction of 1-y-aged wines was also determined. The addition of tannins allowed the increase of the phenolic content of musts and wines in a greater amount than the other technologies. The results concerning the antioxidant activity depended on the method applied. Concerning musts, the DPPH assay did not highlight great differences among technologies, whereas the addition of tannins allowed the obtainment of the highest antioxidant activity according to beta-carotene and ABTS assays. The wine aging determined an increase of the antioxidant activity, independently on the method applied. Wine obtained through traditional technology, saignée, and addition of tannins showed the highest antioxidant activities according to DPPH and beta-carotene. The highest correlation coefficients (0.961 and 0.932) were calculated between phenolic content and ABTS values of musts whereas the lowest values (0.413 and 0.517) were calculated between phenolic content and ABTS values of wines. Wines produced through traditional technology were the richest in anthocyanins. The addition of tannins allowed to obtain high content in monomeric anthocyanins, flavonoids, flavans reactive to vanillin, and coumaroylated malvidin and a low content in acetylated malvidin. Practical Applications: It is well known that a moderate consumption (equivalent to 2 glasses per day) of red wine is actually recommended since it appears associated with a decreased incidence of cardiovascular diseases. The mechanisms involved in this protective effect are not completely understood although they appear related to the presence of phenolic compounds. To increase the intake of these compounds without increase of the wine consumption, it is necessary to improve their extraction during maceration. This study could represent a helpful tool for wineries aimed to know the way to increase the antioxidant content of their wines, thus changing them in functional beverages and prolonging their shelf life.

Varietal differences among the phenolic profiles and antioxidant activities of seven table grape cultivars grown in the south of Italy based on chemometrics.

Seven table grape cultivars grown in Apulia region were considered: Italia, Baresana, Pizzutello, Red Globe, Michele Palieri, Crimson Seedless, and Thompson Seedless. Seeds, skins and pulps were extracted and analyzed for their phenolic profiles and antioxidant activities. The hierarchy in the phenolic contents was seeds, skins, and pulps. These results indicate that the intake of the whole berries (seeds included) must be strongly recommended. The highest phenolic contents were detected on Italia and Michele Palieri cv., respectively within the white and the red/black table grapes. Seeds gave a high contribution to the berry antioxidant activity, as they had higher phenolic content than skins and contained high quantities of proanthocyanidines, but the strongest antioxidant activity was shown by the pulp juices due to their content in hydroxycinnamyl acids. The principal component analysis applied to the phenolic composition and antioxidant activity of skins, pulps, and seeds allowed a good separation of Italia and Michele Palieri cultivars. According to the cluster analysis, cultivars were grouped into two clusters, one including Michele Palieri and the other one including Italia, Baresana, Pizzutello, and Thompson Seedless.

Imaging Techniques for the Study of Food Microstructure: A Review

Publisher Summary This chapter presents a review on imaging techniques for the study of food microstructure. The quality of a food product is related to its sensorial—shape, size, color, and mechanical (texture) characteristics. These features are strongly affected by the food structural organization that can be studied at molecular, microscopic, and macroscopic levels. In particular, the microstructure and interactions of components, such as protein, starch, and fat, determine the texture of a food that could be defined as the ‘‘external manifestation of this structure.’’ Because the microstructure affects food sensorial properties, foods having a similar microstructure also have a similar behavior. Studies on food microstructure can be performed by means of a large variety of techniques allowing the generation of data in the form of images. With the development of more powerful tools, such as the X-ray-computed tomographic scanners, both 2D and 3D digital images of the food internal structure can be readily acquired with high resolution and contrast and without any sample preparation. These images can be processed by means of the fractal and stereological analysis to quantify a number of structural elements. Fractal analysis allows the investigation of the fractal geometry in both 2D and 3D digital images.

Effects of different vinification technologies on physical and chemical characteristics of Sauvignon blanc wines.

In order to investigate the effects of cryomaceration and reductive vinification on chemical and physical indices and on antioxidant compounds of Sauvignon blanc wines, four wine-making procedures were applied: traditional white vinification, skin cryomaceration, vinification in a reductive environment, and a combination of the last two procedures. Significant differences were highlighted by both conventional analyses and NMR spectroscopy. The strongest changes were for organic acid concentrations (tartaric, in particular) and phenolic content. Cryomaceration caused a strong precipitation of tartaric acid, which may be desired if grapes have high acidity values. Cryomaceration protected those flavans reactive with vanillin from the action of oxidative enzymes. Vinification in a reductive environment, alone or combined with a cryomaceration step, gave wines with the highest solids content and caused a greater extraction of phenolic compounds from skins compared to traditional winemaking or cryomaceration alone, due to SO(2) solubilisation. Grape oenological expression can be strongly affected by the application of the investigated wine-making procedures.

Use of biodegradable films for fresh cut beef steaks packaging

A comparative study on the use of biodegradable films for fresh cut meat packaging is presented. Beef steaks were packaged using three different films: polyvinyl chloride (PVC), which is actually used to package this food product, a biodegradable polymeric film composed of starch and polyester and a biodegradable film composed of a mixture of three biodegradable polyesters. The packaged beef steaks were stored at 4 and 15 °C to simulate actual storage conditions and thermal abuse, respectively. Colour, total viable counts as well as spoilage microorganism counts were monitored over a period of 6 days. No substantial differences were observed among the beef steaks packaged using the three investigated films, suggesting that biodegradable films, such as those used in this investigation, could be advantageously used to replace PVC films in packaging of fresh processed meat, reducing in this way the environmental impact of polymeric films.

Selection of Autochthonous Saccharomyces cerevisiae Strains as Wine Starters Using a Polyphasic Approach and Ochratoxin A Removal

Over the last few years, the selection of autochthonous strains of Saccharomyces cerevisiae as wine starters has been studied; however, researchers have not focused on the ability to remove ochratoxin A (OTA) as a possible trait to use in oenological characterization. In this article, a polyphasic approach, including yeast genotyping, evaluation of phenotypic traits, and fermentative performance in a model system (temperature, 25 and 30°C; sugar level, 200 and 250 g liter(-1)), was proposed as a suitable approach to select wine starters of S. cerevisiae from 30 autochthonous isolates from Uva di Troia cv., a red wine grape variety grown in the Apulian region (Southern Italy). The ability to remove OTA, a desirable trait to improve the safety of wine, was also assessed using enzyme-linked immunosorbent assay. The isolates, identified by PCR-restriction fragment length polymorphism analysis of the internal transcribed spacer region and DNA sequencing, were differentiated at strain level through the amplification of the interdelta region; 11 biotypes (I to XI) were identified and further studied. Four biotypes (II, III, V, VIII) were able to reduce OTA, with the rate of toxin removal from the medium (0.6 to 42.8%, wt/vol) dependent upon the strain and the temperature, and biotypes II and VIII were promising in terms of ethanol, glycerol, and volatile acidity production, as well as for their enzymatic and stress resistance characteristics. For the first time, the ability of S. cerevisiae to remove OTA during alcoholic fermentation was used as an additional trait in the yeast-selection program; the results could have application for evaluating the potential of autochthonous S. cerevisiae strains as starter cultures for the production of typical wines with improved quality and safety.

In vitro removal of ochratoxin A by two strains of Saccharomyces cerevisiae and their performances under fermentative and stressing conditions.

The aim of this research was to study the effect of time, temperature, sugar content and addition of diammonium phosphate (DAP) on ochratoxin A (OTA) removal by two strains of Saccharomyces cerevisiae using a completely randomized design.

Effects of defoliation on quality attributes of Nero di Troia (Vitis vinifera L.) grape and wine

Field studies were conducted in Puglia (Italy) to evaluate the influence of defoliation around cluster zones on grape and wine quality. Nero di Troia grapes were subjected to four different treatments: N: no leaf removal; E: leaf removal in the area of the clusters along the east side (at complete veraison); E/W: leaf removal in the area of the clusters along the east and west side (at complete veraison); and F: almost complete leaf removal along the west side (at complete veraison) and at pre-harvest also along the east side. Grapes of defoliated vines generally showed higher sugar content, lower titratable acidity, total flavonoids, flavonoids different from anthocyanins, and total phenolic content than grapes from non-defoliated vines while their total anthocyanin concentration was not affected by defoliation at a significant level. Concerning wines, alcohol content, residual soluble solids, different forms of anthocyanins but also volatile acidity were generally higher in samples from defoliated vines. Differences were also highlighted among the defoliation treatments: the best results in terms of dry matter, sugar and alcohol content were observed in the samples submitted to the more severe defoliation as a consequence of the higher light availability and berry temperature. Concerning the concentration of the individual phenolics, significant differences were highlighted for: caffeic and caftaric acids, peonidin- and malvidin-3-p-coumaroylglucoside, which were higher in the E wines; quercetin-3-glucoside, galactoside, and rhamnoside, and procyanidins, which were higher in F wines.