A versatile and popular Cucurbitaceous vegetable, pumpkin has recently gained much attention because of its variety of phytochemicals and health advantages. Pumpkins are a type of winter squash, traditionally with large, spherical, orange fruits and a highly nutrient food. Pumpkin by-products comprise various parts, such as seeds, peels, and pulp residues, with their bioactive composition and many potential benefits poorly explored by the food industry. Pumpkin and their by-products contain a wide range of phytochemicals, including carotenoids, polyphenols, tocopherols, vitamins, minerals, and dietary fibers. These compounds in pumpkin by-products exhibit antioxidant, anticancer, anti-inflammatory, anti-diabetic, and antimicrobial properties and could reduce the risk of chronic diseases. This comprehensive review aims to provide a detailed overview of the phytochemicals found in pumpkin and its by-products, along with their extraction methods, health benefits, and diverse food and industrial applications. This information can offer valuable insights for food scientists seeking to reevaluate pumpkin’s potential as a functional ingredient. Reusing these by-products would support integrating a circular economy approach by boosting the market presence of valuable and sustainable products that improve health while lowering food waste.

The thermal degradation of the anthocyanins and antioxidant activity in purple maize extracts was determined between 80 and 180 °C. The anthocyanins were found to be thermostable in the temperature range of 80 to 120 °C, whereas at higher temperatures the thermal degradation of both anthocyanins and antioxidant activity followed a first-order kinetic model. The z-values started from 61.72 ± 2.28 °C for anthocyanins and 75.75 ± 2.87 °C for antioxidant activity. The conformational space of pairs of model anthocyanin molecules at 25 and 180 °C was explored through a molecular dynamics test, and results indicated the occurrence of intermolecular self-association reactions and intramolecular co-pigmentation events, which might help explaining the findings of the degradation kinetics. The relationship between thermal degradation of anthocyanins and antioxidant activity and the in vitro release was further studied. The unheated extracts showed a high stability under gastric environment, whereas after heating at 180 °C, the digestion ended quickly after 60 min. After simulated intestinal digestion, the anthocyanins were slowly decreased to a maximum of 12% for the unheated extracts, whereas an 83% decrease was found after preliminary heating at 180 °C. The thermal degradation of anthocyanins was positively correlated with the in vitro decrease of antioxidant activity.

Significant waste streams produced during winemaking include winery by-products such as pomace, skins, leaves, stems, lees, and seeds. These waste by-products were frequently disposed of in the past, causing resource waste and environmental issues. However, interest has risen in valorizing vineyard by-products to tap into their latent potential and turn them into high-value products. Wine industry by-products serve as a potential economic interest, given that they are typically significant natural bioactive sources that may exhibit significant biological properties related to human wellness and health. This review emphasizes the significance of winery by-product valorization as a sustainable management resource and waste management method. The novelty of this review lies in its comprehensive analysis of the potential of winery by-products as a source of bioactive compounds, extraction techniques, health benefits, and applications in various sectors. Chemical components in winery by-products include bioactive substances, antioxidants, dietary fibers, organic acids, and proteins, all of which have important industrial and therapeutic applications. The bioactives from winery by-products act as antioxidant, antidiabetic, and anticancer agents that have proven potential health-promoting effects. Wineries can switch from a linear waste management pattern to a more sustainable and practical method by adopting a circular bioeconomy strategy. Consequently, the recovery of bioactive compounds that function as antioxidants and health-promoting agents could promote various industries concomitant within the circular economy.

This study aimed to use eggplant peels as a potential source of anthocyanins with biological activities. Two different extraction methods were tested in order to obtain extracts with a high anthocyanin content. The selected methods were the solid–liquid extraction (SLE) and ultrasound-assisted extraction (UAE) methods. For each method, two concentrations of ethanol (EtOH) were used, while varying the extraction time and temperature. Based on the results, the extracts obtained by SLE using EtOH 96% after 30 min of extraction at 50 °C showed the highest anthocyanin concentration. The UAE allowed the best results with EtOH 96% after 30 min at 25 °C. Both selected extracts showed similar chromatographic profiles, with delphinidin 3-O-rutinoside as the major anthocyanin, but in a higher concentration in UAE. The extracts also presented inhibitory activity against lipoxygenase (LOX), lipase, and α-amylase, thus suggesting a possible involvement in reducing the risk of various disorders. The first order kinetic model was used to predict the changes that can occur in the anthocyanin content and antioxidant activity from the eggplant peel extract. The calculated kinetic and thermodynamic parameters confirm the irreversible degradation of phytochemicals.

Beetroot (Beta vulgaris), a root vegetable known for its vivid natural color and nutritional profile, is a source of a wide range of bioactive compounds, including betalains, phenolics, vitamins, and antioxidants. These bioactive compounds are associated with many health-promoting properties, including antihypertensive, antioxidant, anti-inflammatory, and anticancer effects. The beetroot processing industry produces substantial by-products abundant in phytochemicals and betalains, presenting valuable opportunities for utilization. Therefore, it can replace synthetic additives and enhance the nutritional value of foods. By reducing waste and supporting a circular economy, beetroot by-products improve resource efficiency, cut production costs, and lessen the food industry’s environmental impact. Beetroot and its by-products are rich in phytochemicals that provide various wellness advantages. They support cardiovascular health, inhibit microbe-induced food spoiling, aid liver function, and reduce inflammation and oxidative stress. This paper presents a detailed review of current knowledge on beetroot and its by-products, focusing on their biochemical components, extraction and stabilization techniques, health benefits, and potential applications in the food industry. It underscores the versatility and importance of red beetroot and its derivatives, advocating for further research into optimized processing methods and innovative uses to enhance their industrial and nutritional value. By providing valuable insights, this review aims to inspire food scientists, nutritionists, and the agricultural sector to integrate beetroot and its by-products into more sustainable and health-oriented food systems.