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Waste from fruits and vegetable processing industry is produced in large quantities worldwide and it contains high levels of lignocellulose, fibre, sugar, bioactive and functional compounds. Their utilisation has become one of the main important and challengeable aspects due to the generation of large quantities of by-products including peels, seeds, leaves and unused flesh in different steps of processing chain. Many researches have validated the waste utilisation as novel, low-cost, economical and natural sources of dietary fibre, antioxidants, pectin, enzymes, organic acids, food additives, essential oils, etc. through different methods of extractions, purifications and fermentations. Though, obtaining these by-products from such a variable substrate requires an understanding of the composition of the polysaccharides and their associations within the overall substrate. Focus on the pineapple fruit, scientific and technological studies have already highlighted and confirmed the potential of better and more profitable markets for pineapple wastes. This review is first of all the collection of previous reports about valorisation of food processing waste, deepening the possibilities of pineapple waste utilisation and to promote the integral exploitation of the by-products rich in bioactive compounds, even as multifunctional food ingredients. More in detail, this review aims at identifying those processes that can be implemented even in disadvantaged areas by means of technologies that allow recovering waste directly on site, thus reducing pollution and providing ingredients/food products with high nutritional values that could be integrated into the diet.

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Background: While there has been an increasing interest in the health properties of chocolate, limited research has looked into the changes of antioxidants occurring in the time span from production to the best before date, which was a period of 18 months in this study. Methods: Humidity, ash, pH, acidity, fiber, carotenoids, retinols, tocopherols, sugars, proteins, theobromine, caffeine, polyphenols, fats, the peroxide value, organic acids, and volatile compounds, along with the sensory profile, were monitored at 18-week intervals for 18 months under conditions simulating a factory warehouse or a point of sale. Results: At the end of the storage period, more polyphenols were lost (64% and 87%) than vitamin E (5% and 14%) in cocoa mass and cocoa powder, respectively. Conversely, a greater loss in vitamin E (34% and 86%) than in polyphenols (19% and 47%) was shown in the hazelnut paste and gianduja chocolate, respectively. The sensory profiling of cocoa mass, cocoa powder, and hazelnut paste revealed increases in grittiness and astringency, as well as decreases in melting, bitterness, and toasted aroma. Moreover, in the hazelnut paste and gianduja chocolate, oiliness increased with a toasted and caramel aroma. Furthermore, dark chocolate was more gritty, acidic, and bitter. Milk chocolate lost its nutty aroma but maintained its sweetness and creaminess. Conclusions: These results should contribute an important reference for companies and consumers, in order to preserve the antioxidants and understand how antioxidants and sensory properties change from the date of production until the best before date.

This work aims to report on the processing of pineapple (Ananas comosus) peel and core into quality wines by combining physical and enzymatic treatments of waste and alcoholic fermentation of the pineapple must with three strains of Saccharomyces cerevisiae (TT, AW, EM2) at three different temperatures (25C, 20C, 15C). The main parameters of the alcoholic fermentation (yeast growth, ethanol production and sugar consumption) were monitored; the fixed and the volatile compounds of pineapple wines were characterized by means of HPLC and GC‐MS techniques. Results outlined that the highest levels of ethanol, i.e., more than 7 and 8% vol/vol, were reached in 96 h when the fermentation was carried out at 20 and 25C with AW and TT strains, respectively. Differently, the fermentation at 15C with EM2 achieved the highest ethanol concentration (7.60% vol/vol) after 120 h and maintained higher levels of citric and malic acid. Accordingly, as the ethanol increases a simultaneous decrease in simple sugars was observed: glucose fell faster than fructose and reached concentrations below 1 g/L after 120 h of fermentation. Significantly different aroma profiles were measured in the wines by changing temperature and strain of S. cerevisiae: the fermentation with AW at 20C produced the highest concentration of acetate and ethyl esters that increased the fruity character of pineapple wine, whilst varietal aroma was enhanced by both fermentations at 25C and 15C with TT and EM2, respectively. However, no variations in pH and acidity during fermentation and very low levels of acetic acid in any pineapple wine sample stressed the aptitude to human consumption of pineapple wines obtained from pineapple waste under this study. Practical Applications Outcomes of the study are important to the industry and highlighted the feasibility of processing tropical fruit waste to obtain added value food products. Furthermore, the results of this work updated the small amount of information published to date on the processing of pineapple waste (or of other tropical fruits) into food grade products, and on the volatile compounds of pineapple wine. As a consequence, the process of conversion of pineapple waste into wine when properly scaled‐up may be transferred to industries that are located either in tropical areas, or in developing countries where the waste is not utilized yet.