Antioxidant phenolic compounds were extracted from fermented samples of Golden pineapple peels via an ultrasound method. The fermentation conditions to maximize the production of phenolic content and antioxidant activity were previously determined (pH: 5.5, T: 37.3 °C and 85% moisture content). A central composite design with 20 treatments was applied to evaluate the effect of the ethanol concentration, time, and temperature on the production of phenolic compounds and antioxidant activity of the extracts. The statistical analysis showed that the optimal conditions to produce extracts with high phenolic content and antioxidant activity were: 62 °C, 30 min and 58% ethanol. We obtained 866.26 mg gallic acid equivalents (GAE)/g d.m in total phenolic content and for antioxidant activity expressed as percentage inhibition, 80.06 ± 1.02% for ABTS and 63.53 ± 2.02% for DPPH, respectively. The bioactive compound profile in the extracts was identified and quantified using ultra-high performance liquid chromatography (UHPLC), this method showed the presence of rosmarinic acid, caffeic acid, vanillic acid, p-coumaric acid, ferulic acid, quercetin-3 glucoside, rutine, quercetin, kaempherol-3 glucoside and gallic acid, demonstrating the great potential of these by-products to obtain components that can benefit the consumer’s health.

Tea (Camellia sinensis) is an evergreen shrub that is recognized worldwide for its functional properties. The current global production of green tea is approximately 5.3 million tons per year. Green tea processing has severely affected the generation of agro-industrial waste. One strategy for reducing waste accumulation is the revalorization of agro-industrial wastes via solid-state fermentation (SSF). The aim of this study was to valorize green tea processing residues to produce tannase under SSF using an endemic strain from Western Ghats, Aspergillus niger TBG 28A. SSF was performed in Erlenmeyer flasks with spent green tea leaves inoculated with spores of A. niger TBG 28A. Bioprocess optimization was carried out by employing the Box–Benkhen experimental design, achieving a high enzymatic yield of 246.82 (U/g). The present study shows the complexity of the degradation of tannins and the different patterns of expression of fungal tannase obtained from A. niger TBG 28 A. The enzyme was further purified to obtain a fold purification of 16.35% and a molecular mass of 150 kDa. Producing tannase with a novel strain of A. niger TBG 28A is an interesting strategy to revalorize green tea waste.

Proteases are important enzymes because of their extended uses in several industries, such as food, beverages, pharmacy, detergents, and many others. Aspergillus is one of the most used fungi strains for enzyme production by solid-state fermentation (SSF). Disponibility of the carbon source is a key factor for protease production. In addition, the selection of solid support has great importance, as it must provide suitable airflow through the packed bed and nutrient diffusion inside the fermentable mass. Six Aspergillus strains and two inert supports (Agrolite (AL) and Polyurethane (PUF)) were tested for protease production from fish flour (FF) at different glucose concentrations (0, 5, 10, 15%) by SSF. The FF/PUF mixture at 70/30 (w/w) ratio, with 75.39% moisture, and a critical moisture point of 0.11 gH₂O/g, presented a texture that allowed heat and mass transfer and provided enough moisture to make free water available as required for microorganism growth during the fermentation process. Aspergillus oryzae 2095 produced higher amounts of neutral and alkaline proteases with the addition of 5% glucose to the growth medium. Kinetics studies reveal that protease production is partially associated with growth. The extracts obtained can be used in different industries, and especially to prepare fish high-value by-product hydrolysates.

Wheat-based bakery products are important sources of energy and micronutrients; however, their protein content is lower than that of animal-based foods, and they generally have a high glycemic index. Therefore, incorporating other ingredients could improve the nutritional properties of this type of product. The partial replacement of wheat flour with flours made from other cereals, legumes, and oilseeds has been evaluated, which complements the amino acid profile, improves the rheological properties of the dough, and increases the content of polyunsaturated fatty acids, fiber, vitamins, and minerals. Similarly, the addition of flour from insects has recently gained relevance due to its high biological value protein content, as well as its low production costs and reduced environmental impact. On the other hand, the use of agro-industrial residues such as cheese whey has stood out for its potential for addition to some bread and pastry products, increasing their nutritional value. Therefore, the incorporation of alternative proteins is becoming a valuable tool for developing these types of products, improving their nutritional properties to prevent or control chronic diseases such as obesity, diabetes, hypertension, etc. However, it is important to analyze the incorporation of these ingredients at each stage of production to achieve adequate rheological properties. Likewise, it is necessary to evaluate consumer acceptance, product safety, and the corresponding regulations. This review will address different options for alternative ingredients that can partially replace wheat-based formulations, as well as how they impact the nutritional value and techno-functional properties of these products.