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.

The present review aimed to investigate and analyze the use of byproduct apple pomace as a fortification ingredient in different types of foods. The data obtained from English published articles found on Web of Science, Scopus, and Google Scholar in the period from 2007 to 2019 were used for making the table overview and meta-analysis of results described in those studies. The systematic review confirmed the importance of apple pomace use in the food industry due to the beneficial nutritional profile and ecological issue (waste management). The main attributes of apple pomace are high content of antioxidant compounds and dietary fibers. Dietary fibers from apple pomace significantly increased total fiber content in enriched products-meaning that the transfer of the fortification can be declared health beneficial. The conducted meta-analysis showed unambiguously the different influence of apple pomace addition according to fortified food commodity. The fortification drawbacks were noticeable in plant food products because darker and brownish color was not evaluated positively by panelists. Oppositely, color, as one of the main sensory characteristics, was beneficially affected in animal origin food. The sensory properties, including color, play an important role in product acceptance by consumers. Besides color, animal origin products fortified by apple pomace showed the most acceptable textural properties and oxidative stability.

The aim of the research was to produce edible packaging based on chitosan with the addition of various concentrations of extracts of blueberry, red grape and parsley marcs. Packaging was made from extrudate extracts, which were subsequently analyzed by physicochemical methods: zeta-potential, gas barrier properties, thickness, water content, solubility, swelling degree, textural properties, total polyphenol content (TPC), polyphenols by high pressure liquid chromatography (HPLC), antioxidant activity, attenuated total reflectance Fourier-Transform spectroscopy (FTIR), antimicrobial activity and determination of migration of bioactive substances. The results indicate that a higher content of plant extracts have a statistically significant (p < 0.05) influence on properties of experimentally produced edible films. Edible films produced with the highest concentrations of red grapes marc extracts showed the most advantageous properties since antimicrobial activity against E. coli were the highest in this kind of produced film. The physical properties of edible films were also improved by the addition of extracts; gas permeability toward oxygen can be defined as advantageous, as can swelling degree, which decreased with higher concentrations of extracts. The research emphasized the possibility to use plant foodstuffs by-products in the production of edible/biodegradable films, helping in the overall sustainability and eco-friendliness of food/package production.

The study aimed to enrich waffle products with grape seed flour, but without affecting their sensory properties. The grape seed flour was obtained from grape pomace, and as an ingredient rich in bioactive compounds such as fiber, polyphenols and minerals, it was used to fortify waffles in concentrations of 1, 3, 5 and 10%. The results for the total polyphenolic content, ferric ion reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picryl-hydrazyl (DPPH) inhibition, showed the highest effect with 10% grape seed flour fortification, including 1.25 mg of gallic acid equivalent/g, 5.62 µmol Trolox/g and 26.65% DPPH inhibition, respectively. Texture analysis revealed an increase in hardness of the waffles along with the increase of grape seed flour percentage, while there was no evident change in moisture in any of the tested samples. Sensory evaluation showed no significant differences regarding overall impression or the estimated price value for all samples, even though evident changes were noted by the panelists in their color, consistency and sweetness. It may be concluded that fortification was successfully carried out, and that there is a great potential for utilizing grape seed flour as a by-product in the enrichment of products such as waffles.

The study aimed to describe the utilization of waste frying oils, originated mainly from households, in home-made soap production and to emphasize the advantages of soap biodegradation in comparison to biological treatment of oils. The physicochemical analyses of soaps were used to check the differences between the samples made of fresh and fried oils. Significant (p < 0.05) difference between the soaps made of fresh/fried olive oil pair was obtained, while the rapeseed sample pair did not differ significantly (p < 0.05). Malondialdehyde (MDA) exhibited notable differences with an increase from 1.94 μg/g to 2.33 μg/g for olive oil fresh/fried pair and from 3.43 μg/g to 4.10 μg/g for rapeseed–palm oil fresh/fried pair. The studies addressing the soap biodegradation process revealed that soaps are degrading up to four times faster than oils in waste processing plants. Literature data showed the syntrophic ways of soap degradation and degradation solely done by sulfate-reducing bacteria. Obtained results, same as literature data, indicated that soaps produced from fried plant oils represent acceptable products from the economic and environmental point of view. Soap production can be considered one of the possible ways toward reduction of waste oil disposal.