Chemical Characterization and Bioaccessibility Assessment of Bioactive Compounds from Umbu (Spondias tuberosa A.) Fruit Peel and Pulp Flours

Functional compounds in tropical fruit processing by-products and intrinsic factors affecting their composition: A review

Tropical fruits, highly demanded in the food industry, generate a considerable amount of waste during processing. These traditionally discarded by-products, such as peels, seeds and pomace, are rich in bioactive compounds, natural molecules that have beneficial properties for human health, as they participate in various metabolic processes in the organism. Among the most prominent compounds are flavonoids, carotenoids, phenolic compounds, tannins and vitamin C. Beyond their health benefits, these compounds have significant industrial value and are widely used in the textile, pharmaceutical, cosmetic, biotechnological and food fields, in the latter especially as preservatives, additives, colorants and others. This review explores the main bioactive compounds found in fruit by-products, highlighting their functional relevance and analyzing the intrinsic or fruit-derived factors that influence the composition of these compounds, such as the type of by-product (peels, seeds, bagasse, pomace), the variety of fruit, and the state of maturity at the time of processing. In addition, the extraction methods used to obtain these compounds are addressed, differentiating between conventional techniques, such as solvent extraction, and emerging methods, such as ultrasound-assisted extraction and supercritical fluid extraction, which offer advantages in terms of efficiency and sustainability. The diversity of bioactive compounds and their potential application in various industries highlight the importance of ongoing research in this field. It is necessary to further study the factors that influence the composition of these compounds, as well as the development of more efficient and sustainable extraction methods. These advances will not only add value to food industry waste, but will also contribute to the development of natural products with health benefits.

Alternative flours from pulp melons (Cucumis melo L.): Seasonality influence on physical, chemical, technological parameters, and utilization in bakery product

Fresh vegetables have high water content and low acidity, so drying can extend shelf life, allowing the obtaining of alternative flours for the development of new products. The study aimed to investigate the influence of the melon harvest and off-season on the chemical composition of melon (Cantaloupe, Charentais e Honey Dew) flours and the potential application in products. The flours were evaluated for granulometry, morphology, centesimal composition, lipid and mineral content, total phenolic compound (TPC), antioxidant activity, and technological properties. Cakes containing melon flour were produced to replace wheat flour (0, 25, and 50 %) and evaluated for proximate composition, microbiology, and sensory parameters. Flours were classified as fine-grained (MESH >16), except Charentais off-season (medium - MESH 8-16, and fine-grained - MESH >16), and all presented a rough surface and minimal cell wall ruptures. The harvest homogeneously influenced the humidity, as all the off-season flours showed higher levels [17-22 %] (p < 0.05) due to weather conditions. For TPC, Cantaloupe melon flours from the harvest (CFH) [208 mg/100 g] and off-season [877 mg/100 g] stood out (p < 0.05), and the latter showed greater antioxidant potential [328 μmol TE/g]. Palmitic, linoleic, and linolenic acid stood out in all flours, and potassium for minerals (63-78 %) in the harvest and off-season. The harvest and off-season specifically influenced the flour of each variety in swelling power, water solubility, oil absorption, and emulsifying capacity. For cakes with CFH, no thermotolerant coliforms and Escherichia coli were detected, and the mesophilic count was <1.0 CFU/g. The ash, protein, lipid, and fiber contents increased proportionally to melon flour addition (p < 0.05). Sensory acceptance was high for cakes containing 25 and 50 % of CFH [82.78 % and 82.53 %], and most consumers would likely buy the products (4.04 and 3.99) (p < 0.05). The study contributed to knowledge about the seasonality effect and demonstrated the potential use of melon flour in developing new products.

Melon peel flour: utilization as a functional ingredient in bakery products

Food by-products are a major concern with a direct impact on the economy, society, and environment. The valorisation of these by-products could be an advantageous approach to face the increase in food waste since it can compromise environmental health and food sustainability. On the other hand, this valorisation would allow the development of new food products with health benefits for the population. Cucumis melo L. is a highly consumed fruit all over the world since it has excellent sensory and nutritional qualities, being also a good source of bioactive compounds. However, its peel and seeds are usually discarded. The aim of this study was to evaluate the potential of melon peel flour as a functional ingredient for innovative food products. For that, two different formulations containing melon peel flour were developed (a biscuit and a muffin) by replacing a conventional flour (wheat flour) in different percentages (50% and 100%, respectively). The nutritional composition, total phenolic content, and antioxidant potential of the developed products were studied, showing a high content of fibre, high levels of phenolic compounds and good sensory acceptability. These results show that it is possible to enrich different foods with melon peel flour in order to improve their nutritional properties, contributing to improving public health, simultaneously valorising a usually rejected by-product, reducing food waste and the environmental impact.

Characterizations and effects of pectin-coated nanoliposome loaded with Gijavash (Froriepia subpinnata) extract on the physicochemical properties of cheese

In this study, pectin-coated nanoliposomes containing Gijavash extract were used to formulate cheese and evaluate its shelf life, physicochemical, and sensory aspects. The study used a central composite design with three independent variables to prepare the cheese. The results showed that the optimal particle size, zeta potential, encapsulation efficiency, and DPPH radical antioxidant activity were 201.22 nm, -29.33 mV, 61.87%, and 57.54%, respectively. Adding nanoliposomes with varying extract amounts improved pH and lowered acidity in fortified cheeses. Moisture and lipolysis indices also improved after applying nanoliposomes. Sensory evaluation revealed that sensory acceptance was highest in the cheese with 15% extract. The study suggests that adding pectin-coated nanoliposomes containing Gijavash extract to cheese formulations may create novel products and improve their physicochemical properties.

By-Products of Fruit and Vegetables: Antioxidant Properties of Extractable and Non-Extractable Phenolic Compounds

Non-extractable phenolic compounds (NEPs), or bound phenolic compounds, represent a crucial component of polyphenols. They are an essential fraction that remains in the residual matrix after the extraction of extractable phenolic compounds (EPs), making them a valuable resource for numerous applications. These compounds encompass a diverse range of phenolic compounds, ranging from low molecular weight phenolic to high polymeric polyphenols attached to other macro molecules, e.g., cell walls and proteins. Their status as natural, green antioxidants have been well established, with numerous studies showcasing their anti-inflammatory, anti-aging, anti-cancer, and hypoglycemic activities. These properties make them a highly desirable alternative to synthetic antioxidants. Fruit and vegetable (F&Veg) wastes, e.g., peels, pomace, and seeds, generated during the harvest, transport, and processing of F&Vegs, are abundant in NEPs and EPs. This review delves into the various types, contents, structures, and antioxidant activities of NEPs and EPs in F&Veg wastes. The relationship between the structure of these compounds and their antioxidant activity is explored in detail, highlighting the importance of structure-activity relationships in the field of natural antioxidants. Their potential applications ranging from functional food and beverage products to nutraceutical and cosmetic products. A glimpse into their bright future as a valuable resource for a greener, healthier, and more sustainable future, and calling for researchers, industrialists, and policymakers to explore their full potential, are elaborated.

Umbu Fruit Peel as Source of Antioxidant, Antimicrobial and α-Amylase Inhibitor Compounds

Herein, the extraction of bioactive compounds from umbu fruit peel was optimized using thermal-assisted solid-liquid extraction. In parallel, antioxidant, antimicrobial, and inhibitory effects against α-amylase of optimized extract were also evaluated. The combination of operational conditions including the temperature (32-74 °C), ethanol concentration (13-97%), and solid/liquid ratio (1:10-1:60; w/v) was employed using a rotational central composite design for optimization. The extracts were evaluated for total phenolic compounds (TPC), total flavonoid compounds (TFC) and antioxidant capacity by ABTS•+, DPPH• and FRAP assays. The bioactive profile of the optimized extract was obtained by ultra-performance liquid chromatography coupled to quadrupole/time-of-flight mass spectrometry in electrospray ionization in both negative and positive modes. The statistically evaluated results showed that the optimal operational conditions for the recovery of bioactive compounds from umbu fruit peel included 74 °C, 37% ethanol, and a solid-liquid ratio of 1:38. Under these conditions, the obtained values were 1985 mg GAE/100 g, 1364 mg RE/100 g, 122 µmol TE/g, 174 µmol/TE g and 468 µmol Fe2+/g for TPC, TFC, ABTS•+, DPPH•, and FRAP assays, respectively. In addition, the optimized extract was effective against Gram-positive and Gram-negative bacteria (MBC ranged from 0.060 to 0.24 mg GAE/mL), as well as it was effective to inhibit α-amylase (IC50 value of 0.076 mg GAE/mL). The optimized extract showed to be mainly constituted by phenolic acids and flavonoids.