Highly efficient pumpkin-seed extraction with the simultaneous recovery of lipophilic and hydrophilic compounds

Optimization of the Parameters Influencing the Antioxidant Activity and Concentration of Carotenoids Extracted from Pumpkin Peel Using a Central Composite Design

It has been discovered that the peel of a pumpkin (Cucurbita maxima), regarded as a waste product of pumpkin processing, has significant amounts of carotenoids and other antioxidants. This study aims to identify the most effective extraction parameters for an ultrasonic-assisted extraction method to extract the total carotenoids (TCs) and assess the antioxidant activity (AA) of pumpkin peel. To determine the effects of the extraction time, temperature, and material-to-solvent ratio on the recovery of TCs and AA, a response surface methodology utilizing the central composite design (CCD) was used. The extraction temperature (6.25-98.75 °C), extraction duration (13.98-128.98 min), and solvent ratio (0.23-50.23 mL) were the variables studied in the coded form of the experimental plan. The carotenoid concentration varied from 0.53 to 1.06 mg/g DW, while the AA varied from 0.34 to 7.28 µM TE/g DW. The findings indicated that the optimal extraction parameters were an 80 °C temperature, a 10 mL solvent ratio, and a 100 min extraction time. The study confirmed that the optimum extraction conditions resulted in an experimental TC yield of 0.97 mg/g DW and an AA of 7.25 µM TE/g DW. Overall, it should be emphasized that the extraction process can be enhanced by setting the operating factors to maximize the model responses.

Carotenoid Content and Profiles of Pumpkin Products and By-Products

The goal of this review is to provide an overview of the current findings on the major carotenoids and their content in pumpkin products and by-products. The content of total carotenoids and the composition of carotenoids in pumpkins depend mainly on the species and cultivar, pedoclimatic conditions, the part of the plant (pulp, peel or seed), extraction procedures and the type of solvent used for extraction. The major carotenoids identified in pumpkins were β-carotene, α-carotene, lutein and zeaxanthin. β-Carotene is the major carotenoid in most pumpkin species. The number and content of total carotenoids are higher when minor carotenoids and ester forms are considered. The use of carotenoids in the development of functional foods has been the topic of many versatile studies in recent years, as they add significant value to foods associated with numerous health benefits. In view of this, pumpkin and pumpkin by-products can serve as a valuable source of carotenoids.

Unveiling the Bioactive Potential of Fresh Fruit and Vegetable Waste in Human Health from a Consumer Perspective

Food supply disruption and shortage verified during the current pandemic events are a scenario that many anticipate for the near future. The impact of climate changes on food production, the continuous decrease in arable land, and the exponential growth of the human population are important drivers for this problem. In this context, adding value to food waste is an obvious strategy to mitigate food shortages, but there is a long way to go in this field. Globally, it is estimated that one-third of all food produced is lost. This is certainly due to many different factors, but the lack of awareness of the consumer about the nutritional value of certain foods parts, namely peels and seeds, is certainly among them. In this review, we will unveil the nutritional and bioactive value of the waste discarded from the most important fresh fruit and vegetables consumed worldwide as a strategy to decrease food waste. This will span the characterization of the bioactive composition of selected waste from fruits and vegetables, particularly their seeds and peels, and their possible uses, whether in our diet or recycled to other ends.

A comprehensive review on current and emerging technologies toward the valorization of bio-based wastes and by products from foods

Industries in the agro-food sector are the largest generators of waste in the world. Agro-food wastes and by products originate from the natural process of senescence, pretreatment, handling, and manufacturing processes of food and beverage products. Notably, most of the wastes are produced with the transformation of raw materials (such as fruits, vegetables, plants, tubers, cereals, and dairy products) into different processed foods (e.g., jams, sauces, and canned fruits/vegetables), dairy derivatives (e.g., cheese and yogurt), and alcoholic (e.g., wine and beer) and nonalcoholic beverages (e.g., juices and soft drinks). Current research is committed not only to the usage of agro-food wastes and by products as a potential source of high-value bioactive compounds (e.g., phenolic compounds, anthocyanins, and organic acids) but also to the implementation of emerging and innovative technologies that can compete with conventional extraction methods for the efficient extraction of such biomolecules from the residues. Herein, specific valorization technologies, such as membrane-based processes, microwave, ultrasound, pulsed electric-assisted extraction, supercritical/subcritical fluids, and pressurized liquids, have emerged as advanced techniques in extracting various added-value biomolecules, showing multiple advantages (improved extraction yields, reduced process time, and protection to the bioactive properties of the compounds). Hence, this comprehensive review aims to analyze the ongoing research on applying such techniques in valorization protocols. A last-five-year review, together with a featured analysis of the relevant findings in the field, is provided.

Ultrasound-assisted biomass valorization to industrial interesting products: state-of-the-art, perspectives and challenges

Nowadays, the application of ultrasound (US) energy for assisting the lignocellulosic biomass and waste materials conversion into value-added products has dramatically increased. In this sense, this review covers theoretical aspects, promising applications, challenges and perspectives about US and its use for biomass treatment. The combination of US energy with a suitable reaction time, temperature and solvent contributes to the destruction of recalcitrant lignin structure, allowing the products to be used in thermochemical and biological process. The main mechanisms related to US propagation and impact on the fragmentation of lignocellulosic materials, selectivity, and yield of conversion treatments are discussed. Moreover, the synergistic effects between US and alternative green solvents with the perspective of industrial applications are investigated. The present survey analysed the last ten years of literature, studying challenges and perspectives of US application in biorefinery. We were aiming to highlight value-added products and some new areas of research.

Recovery of Natural Antioxidants from Agro-Industrial Side Streams through Advanced Extraction Techniques

Large amounts of agro-industrial waste are being generated each year, leading to pollution and economic loss. At the same time, these side streams are rich source of active compounds including antioxidants. Recovered compounds can be re-utilized as food additives, functional foods, nutra-/pharmaceuticals, cosmeceuticals, beauty products, and bio-packaging. Advanced extraction techniques are promising tools to recover target compounds such as antioxidants from agro-industrial side streams. Due to the disadvantages of classical extraction techniques (such as large amounts of solvents, increased time of extraction, large amounts of remaining waste after the extraction procedure, etc.), and advanced techniques emerged, in order to obtain more efficient and sustainable processes. In this review paper aspects regarding different modern extraction techniques related to recovery of antioxidant compounds from wastes generated in different industries and their applications are briefly discussed.