Current technologies and new insights for the recovery of high valuable compounds from fruits by-products

The recovery of high valuable compounds from food waste is becoming a tighten issue in food processing. The large amount of non-edible residues produced by food industries causes pollution, difficulties in the management, and economic loss. The waste produced during the transformation of fruits includes a huge amount of materials such as peels, seeds, and bagasse, whose disposal usually represents a problem. Research over the past 20 years revealed that many food wastes could serve as a source of potentially valuable bioactive compounds, such as antioxidants and vitamins with increasing scientific interest thanks to their beneficial effects on human health. The challenge for the recovery of these compounds is to find the most appropriate and environment friendly extraction technique able to achieve the maximum extraction yield without compromising the stability of the extracted products. Based on this scenario, the aim of the current review is twofold. The first is to give a brief overview of the most important bioactive compounds occurring in fruit wastes. The second is to describe the pro and cons of the most up-to-dated innovative and environment friendly extraction technologies that can be an alternative to the classical solvent extraction procedures for the recovery of valuable compounds from fruit processing. Furthermore, a final section will take into account published findings on the combination of some of these technologies to increase the extracts yields of bioactives.     

Nutritional,functional and biological properties of insect proteins: Processes for obtaining,consumption and future challenges

BackgroundConsuming insects as an alternative protein source is considered a future trend and a viable strategy that could potentially contribute to global food security. Insects are a non-conventional source of protein, either for human consumption directly or indirectly as a component in recomposed foods or added to feedstock mixtures. Moreover, these proteins have demonstrated a broad range of applications as peptides with antihypertensive, antimicrobial and antioxidant properties. However, aspects such as food safety and processing of these proteins need further studies for their elucidation and optimization.Scope and approachIn this review, aspects of nutritional value and risks of insect consumption are reported. Additionally, conventional processing techniques and recent advances in insect protein extraction and production are presented. The application of bioactive peptides obtained from insect protein hydrolysates is reported, focusing on their potential antihypertensive, antimicrobial and antioxidant properties.Key findings and conclusionsInsect proteins have great advantages in terms of nutritional value, total protein level and amino acid profile. However, some safety concerns must be taken into consideration in large-scale production. The conventional processing of insects proteins is very particular, depending on several aspects such as species, larval stage, and cultivation, among others. Nonetheless, recent advances in insect protein production via enzymatic hydrolysis and heterologous expression have shown a promising technology for the study and exploitation of their bioactive properties, such as the antimicrobial, antioxidant and antihypertensive (inhibition of ACE) activity of insect peptides.     

Valorisation of food wastes to produce natural pigments using non-thermal novel extraction methods: a review

Waste or by-products produced during food processing can be used as a potential source of bioactive compounds including natural pigments. Natural pigments/colourants have numerous health benefits whereas the synthetic colourants have many negative effects on human health. Thus, there is a considerable interest worldwide in pigments extraction from natural sources. Conventional extractions such as soxhlet extraction, water distillation, and solvent extraction have many limitations such as large solvent consumption, long extraction time, and low extraction yields. Therefore, novel techniques such as high pressure, ultrasound, negative pressure and electric field have been employed to assist the pigment extraction process. The novel extraction methods are being developed with the primary aim of higher pigment yield, lower solvent consumption, minimised environmental effects and the convenience of extraction. With this perspective, the present review provides recent insights into the recovery of natural pigments from food wastes/by-products and the application of novel non-thermal technologies for their recovery.     

Biopolymer nanoparticles: a strategy to enhance stability,bioavailability, and biological effects of phenolic compounds as functional ingredients

Phenolic compounds are abundant in nature and have multiple beneficial effects on human health due to their antioxidant, anti-inflammatory, antithrombotic, antiallergenic, anticancer, and antiatherosclerotic properties. For this reason, phenolics are becoming relevant functional ingredients for several industries, mainly the food industry, derived from food consumer exigencies and regulations. However, the use of their beneficial properties still presents some limitations, such as chemical instability under environmental and processing conditions, which leads to structural changes and compromises their biological activities. They also present poor water solubility and sensitivity to pH changes, decreasing their bioavailability in the organism. The technologies for extraction and stabilization of these compounds have evolved rapidly in the development of different delivery systems to encapsulate sensitive active molecules. Biopolymeric nanoparticles are biodegradable polymer-based colloidal systems with sizes ranging from 1 to 1000 nm, and different techniques can be carried out to develop them. These systems have emerged as a green and effective alternative to improve stability, bioavailability, and biological effects of phenolic compounds. This comprehensive review aims to present an overview of recent advances in encapsulation processes of phenolic compounds within biopolymer nanoparticles as delivery systems and the impact on their physicochemical properties and biological effects after encapsulation. © 2021 Society of Chemical Industry.     

Emulsion electrospinning: Fundamentals,food applications and prospects

BackgroundIn the past decades, many natural bioactive compounds with antioxidant, immunoregulatory, antimicrobial, and anticancer activities have been successfully identified in plant and animal materials. However, due to their poor solubility, unfavorable flavor, low bioavailability and instability during food processing and storage, the development of bioactive compounds used in the food industry presents many technological challenges.Scope and approachEmulsion electrospinning is a novel and simple technique to fabricate core-shell nanofibers, and either water-in-oil (W/O) or oil-in-water (O/W) emulsions can be electrospun to directly encapsulate hydrophilic or hydrophobic compounds into core-shell fibers, respectively. This review introduces fundamentals and advantages of emulsion electrospinning as well as its food applications. The effects of different types of emulsifiers on the formation of emulsion systems and emulsion-based electrospun fibers are highlighted. Further, the existing limitations and scope for future research are discussed.Key findings and conclusionsRecent studies have found that the emulsion-based electrospun nanofibers can enhance the encapsulation efficiency, stability, and bioavailability of bioactive compounds, as well as achieve targeted delivery and controlled release, thus providing new strategies to improve their barrier performance compared to conventional electrospinning and therefore facilitating the development of emulsion-based electrospun mats in the food industry.     

静电纺丝技术包埋抗菌物质研究进展

近年来,人们已成功地开发出多种不同来源的天然抗菌物质。由于食品加工和储存条件对其抗菌效果产生很大的影响,极大地限制了其在食品工业中的应用。目前常用的包埋技术在包埋抗菌物质时仍存在许多不足之处。因此,开发出高效包埋天然抗菌物质的包埋技术成为研究的热点问题。静电纺丝技术是一种新颖的、简单的生物活性物质包埋技术,能够显著提高生物活性物质的包埋效率、稳定性和利用度,在一定程度上克服了传统包埋技术在包埋生物活性物质时的弊端。本文主要综述了静电纺丝技术的原理,纺丝参数对静电纺丝纳米纤维的影响以及以多糖和蛋白质为基质利用静电纺丝技术包埋抗菌物质及其应用的研究进展,为其在食品工业中的良好应用奠定基础。     

Emerging technologies to extract high added value compounds from fruit residues: Sub/supercritical,ultrasound-, and enzyme-assisted extractions

Food waste is a growing problem for the food industry, leading to an increase of pollution and economic problems. Fruits and vegetables are very rich in bioactive compounds having many benefits for humans. These biocompounds can be found not only in the fruit/vegetable itself but also in its wastes, after processing. Nonetheless, the conventional extraction methods are highly problematic, due to solvent consumption, long extraction time, and low extraction yields, making it necessary to develop new extraction techniques. In this review, we aim to review the most recent literature on the extraction of bioactive compounds from fruit peels and seeds, using sub/supercritical fluids, ultrasound, and enzymes.     

Ultrahigh pressure extraction of bioactive compounds from plants—A review

Extraction of bioactive compounds from plants is one of the most important research areas for pharmaceutical and food industries. Conventional extraction techniques are usually associated with longer extraction times, lower yields, more organic solvent consumption, and poor extraction efficiency. A novel extraction technique, ultrahigh pressure extraction, has been developed for the extraction of bioactive compounds from plants, in order to shorten the extraction time, decrease the solvent consumption, increase the extraction yields, and enhance the quality of extracts. The mild processing temperature of ultrahigh pressure extraction may lead to an enhanced extraction of thermolabile bioactive ingredients. A critical review is conducted to introduce the different aspects of ultrahigh pressure extraction of plants bioactive compounds, including principles and mechanisms, the important parameters influencing its performance, comparison of ultrahigh pressure extraction with other extraction techniques, advantages, and disadvantages. The future opportunities of ultrahigh pressure extraction are also discussed.     

静电纺丝技术在保护活性成分及益生菌中应用的研究进展

随着近几十年来不同纳米技术的迅速发展,将生物活性成分捕获到高分子基质中进行控释已成为一个热门的研究领域。将生物活性成分加入到不同的封装基质中是一种独特的方法,它可以保护这些有价值的成分在不利的体外或体内环境中不致失活,最大限度的提高其稳定性和生物利用率。与传统封装技术相比,静电纺丝技术具有许多优势,如所产纤维的孔隙率高、表面体积比高、结构上与细胞外基质相似以及对生物活性化合物具有高包封率等,这些结构和功能上的优势使得静电纺丝技术在保护生物活性成分方面成为一种更好的选择。本文主要综述了静电纺丝的基本工作原理、纳米纤维聚合物的选择、影响纳米纤维特性的参数,分析了静电纺丝纳米纤维的优势,并探讨了静电纺丝技术在包封不同类型生物活性化合物中的应用,为该技术在食品加工中的深入研究及应用以及相关创新食品的开发提供了参考。     

Natural phytochemicals and probiotics as bioactive ingredients for functional foods: Extraction,biochemistry and protected-delivery technologies

BackgroundThe well-known correlation between diet and physiology demonstrates the great possibilities of food to maintain or improve our health, increasing the interest in finding new products with positive physiological effects. Nowadays, one of the top research areas in Food Science and Technology is the extraction and characterization of new natural ingredients with biological activity that can be further incorporated into a functional food, contributing to consumer's well-being. Furthermore, there is a high demand for effective encapsulation methodologies to preserve all the characteristics of bioactive compounds until the physiological action site is reached.Scope and approachIn this review, the relevance of developing standard approaches for the extraction of the highly diverse bioactive compounds was described, as it defines the suitability of the following steps of separation, identification and characterization. Special attention was also dedicated to the encapsulation techniques used on hydrophilic and/or lipophilic compounds (e.g., emulsification, coacervation, supercritical fluid, inclusion complexation, emulsification-solvent evaporation and nanoprecipitation).Key findings and conclusionsSome useful conclusions regarding the selection of the best extraction methodology (Soxhlet extraction, ultrasound-assisted extraction, supercritical fluid extraction, accelerated solvent extraction, or shake extraction) were achieved, considering important aspects such as cost, required technical skills, extract integrity, green chemistry principles, solvent type, sample size, pH, temperature and pressure. In addition, this comprehensive review allowed defining the best protective approach to solve the limitations related to the extremely low absorption and bioavailability of bioactive phytochemicals, overcoming problems related to their low solubility, poor stability, low permeability and metabolic processes in the GI tract.     

Agro-industrial potential of exotic fruit byproducts as a source of food additives

Exotic fruit consumption and processing is increasing worldwide due to the improvement in preservation techniques, transportation, marketing systems and consumer awareness of health benefits. The entire body of tropical exotic fruits is rich in bioactive compounds, such as phenolic constituents, carotenoids, vitamins and dietary fiber. However, the fruit processing industry deals with the large percentage of byproducts, such as peels, seeds and unused flesh, generated in the different steps of the processing chains. In most cases, the wasted byproducts can present similar or even higher contents of bioactive compounds than the final produce does. The aim of this review is to promote the production and processing of exotic fruits highlighting the possibility of the integral exploitation of byproducts rich in bioactive compounds. Amongst the possible uses for these compounds that can be found in the food industry are as antioxidants (avoiding browning and lipid oxidation and as functional food ingredients), antimicrobials, flavoring, colorants and texturizer additives. Finally, the importance of extraction techniques of bioactive compounds designated as food additives is also included.     

葡萄渣多酚的分布、生物活性及其在食品中的 应用研究进展

许多水果在加工过程中会产生大量的副产物,如葡萄酒酿造过程中产生的葡萄果渣(grape pomace,GP),由于其中含有丰富的生物活性物质,如多酚、膳食纤维、有机酸和不饱和脂肪酸等,已成为医药、化妆品和食品工业提取植物活性物质的廉价来源。尤其是酚类化合物受到越来越多的关注,葡萄渣中的酚类化合物是一类次生代谢产物,主要包括类黄酮、花青素和白藜芦醇等,很多研究已经证实这些酚类化合物具有抗氧化、抗菌、抗病毒、抗炎和抗癌等生物活性,因此,如何从葡萄渣中提取多酚化合物并将其开发成功能性食品配料,成为越来越多的企业和学者的关注。在此本文对GP多酚的组成分布、生物活性、在食品中的稳定性及其应用等进行了较全面的总结,旨在为葡萄渣多酚功能性食品的开发提供参考。     

Applications of novel processing technologies to enhance the safety and bioactivity of milk

Bioactive compounds in food can have high impacts on human health, such as antioxidant, antithrombotic, antitumor, and anti-inflammatory activities. However, many of them are sensitive to thermal treatments incurred during processing, which can reduce their availability and activity. Milk, including ovine, caprine, bovine, and human is a rich source of bioactive compounds, including immunoglobulins, vitamins, and amino acids. However, processing by various novel thermal and non-thermal technologies has different levels of impacts on these compounds, according to the studies reported in the literature, predominantly in the last 10 years. The reported effect of these technologies either covers microbial inactivation or the bioactive composition; however, there is a lack of comprehensive compilation of studies that compare the effect of these technologies on bioactive compounds in milk (especially, caprine and ovine) to microbial inactivation at similar settings. This research gap makes it challenging to conclude on the specific processing parameters that could be optimized to achieve targets of microbial safety and nutritional quality at the same time. This review covers the effect of a wide range of thermal and non-thermal processing technologies including high-pressure processing, pressure-assisted thermal sterilization, pulsed-electric field treatment, cold plasma, microwave-assisted thermal sterilization, ultra-high-pressure homogenization, ultrasonication, irradiation on the bioactive compounds as well as on microbial inactivation in milk. Although a combination of more than one technology could improve the reduction of bacterial contaminants to meet the required food safety standards and retain bioactive compounds, there is still scope for research on these hurdle approaches to simultaneously achieve food safety and bioactivity targets.     

Grape by‐product extracts against microbial proliferation and lipid oxidation: a review

The wine industry is responsible for the production of million tons of waste, such as grape skin, stalk, sludge and seeds, which can be considered inexpensive sources of phenolic compound owing to incomplete extraction during wine production. Phenolic compounds, also called polyphenols, comprise the most abundant bioactive compounds in grape and are recognized by their antioxidant and antimicrobial potential. Because of their functional properties, extracts obtained from grape wastes, which are rich in phenolic compounds, can be employed in the development of many products, ranging from medical to food applications, decreasing the growth of spoilage and pathogenic microorganisms and inhibiting lipid oxidation. These characteristics are motivating the research for alternative sources of natural antioxidant and antimicrobial agents, aimed at decreasing the use of artificial additives, which have been associated with some toxic effects. This article provides a review of the use of grape by‐product extracts and their bioactive compounds as natural antioxidant and antimicrobial agents in food products. © 2016 Society of Chemical Industry     

莲废弃物活性成分的提取及其生物活性的研究进展

莲子加工过程会产生莲蓬、莲衣、莲子壳、莲子心等废弃物,这些废弃物往往被直接丢弃,而未进一步开发利用,造成了明显的莲资源浪费。由于莲废弃物中含有对人体健康具有促进作用的多酚、生物碱和多糖等多种活性成分,莲废弃物活性成分的开发利用受到了越来越多的关注。目前,常规提取方法和现代提取方法都已被广泛应用于莲废弃物活性成分的提取。与此同时,为了提高提取率,一些新型提取技术也被应用于莲废弃物活性成分的提取并表现出了显著的效果。莲废弃物中的多酚、生物碱和多糖具有抗糖化、抗增殖、抗氧化、抗炎等多种生理活性,但其活性研究主要集中于体外阶段,未来还需要进一步研究其在人体内的功效发挥。本文综述了莲废弃物中主要活性成分的提取方法及其生理活性的研究进展,以期对莲废弃物资源的高附加值开发与利用提供参考。     

Technologies for enhancement of bioactive components and potential health benefits of cereal and cereal-based foods: Research advances and application challenges

Cereal grains are a major source of human food and their production has steadily been increased during the last several decades to meet the demand of our increasing world population. The modernized society and the expansion of the cereal food industry created a need for highly efficient processing technologies, especially flour production. Earlier scientific research efforts have led to the invention of the modern steel roller mill, and the refined flour of wheat has become a basic component in most of cereal-based foods such as breads and pastries because of the unique functionality of wheat protein. On the other hand, epidemiological studies have found that consumption of whole cereal grains was health beneficial. The health benefit of whole cereal grain is attributed to the combined effects of micronutrients, phytochemicals, and dietary fibre, which are mainly located in the outer bran layer and the germ. However, the removal of bran and germ from cereal grains during polishing and milling results in refined flour and food products with lower bioactive compounds and dietary fibre contents than those from whole grain. Also, the level of bioactive compounds in cereal food is influenced by other food preparation procedures such as baking, cooking, extrusion, and puffing. Therefore, food scientists and nutritionists are searching for strategies and processing technologies to enhance the content and bioavailability of nutrients, bioactive compounds, and dietary fibre of cereal foods. The objective of this article was to review the research advances on technologies for the enhancement of bioactive compounds and dietary fibre contents of cereal and cereal-based foods. Bioactivities or biological effects of enhanced cereal and cereal-based foods are presented. Challenges facing the application of the proposed technologies in the food industry are also discussed.     

Phytochemistry Profile,Nutritional Properties and Pharmacological Activities of Mauritia flexuosa

Mauritia flexuosa L. (Arecaceae) is a popular Brazilian fruit known as “buriti” and belonging to the category of functional foods. This work reviewed the phytochemistry profile, nutritional and pharmacological activities of M. flexuosa. The main bioactive compounds reported to buriti were carotenoids, tocopherols, ascorbic acid, phenolic compounds, fiber, phytosterols, and mono‐ and poly‐unsaturated fatty acids. These compounds were mainly related to antioxidant, hypolipemiant, photoprotector, antiaggregant, antithrombotic, anti‐inflammatory, hypoglycemiant, antimicrobial, and antitumor activities. Furthermore, some compounds present in buriti fruit and its properties were tested in vitro and in vivo and showed biotechnology applications, especially for extraction of fiber, polysaccharides, pigments, antioxidants, and oil. Howerer, the buriti fruit shows great relevance to the development of new products in food, pharmaceutical and chemical industry, this fruit is still underexploited and it has need to expand its production chain and processing to encourage their consumption and utilization.     

An updated review of dietary isoflavones: Nutrition,processing, bioavailability and impacts on human health

Isoflavones (genistein, daidzein, and glycitein) are bioactive compounds with mildly estrogenic properties and often referred to as phytoestrogen. These are present in significant quantities (up to 4–5 mg·g^?1 on dry basis) in legumes mainly soybeans, green beans, mung beans. In grains (raw materials) they are present mostly as glycosides, which are poorly absorbed on consumption. Thus, soybeans are processed into various food products for digestibility, taste and bioavailability of nutrients and bioactives. Main processing steps include steaming, cooking, roasting, microbial fermentation that destroy protease inhibitors and also cleaves the glycoside bond to yield absorbable aglycone in the processed soy products, such as miso, natto, soy milk, tofu; and increase shelf lives. Processed soy food products have been an integral part of regular diets in many Asia–Pacific countries for centuries, e.g. China, Japan and Korea. However, in the last two decades, there have been concerted efforts to introduce soy products in western diets for their health benefits with some success. Isoflavones were hailed as magical natural component that attribute to prevent some major prevailing health concerns. Consumption of soy products have been linked to reduction in incidence or severity of chronic diseases such as cardiovascular, breast and prostate cancers, menopausal symptoms, bone loss, etc. Overall, consuming moderate amounts of traditionally prepared and minimally processed soy foods may offer modest health benefits while minimizing potential for any adverse health effects.     

Applications and opportunities for ultrasound assisted extraction in the food industry — A review

Ultrasound assisted extraction (UAE) process enhancement for food and allied industries are reported in this review. This includes herbal, oil, protein and bioactives from plant and animal materials (e.g. polyphenolics, anthocyanins, aromatic compounds, polysaccharides and functional compounds) with increased yield of extracted components, increased rate of extraction, achieving reduction in extraction time and higher processing throughput. Ultrasound can enhance existing extraction processes and enable new commercial extraction opportunities and processes. New UAE processing approaches have been proposed, including, (a) the potential for modification of plant cell material to provide improved bioavailability of micro-nutrients while retaining the natural-like quality, (b) simultaneous extraction and encapsulation, (c) quenching of the radical sonochemistry especially in aqueous systems to avoid degradation of bioactives and (d) potential use of the radical sonochemistry to achieve targeted hydroxylation of polyphenolics and carotenoids to increase bioactivity.Industrial relevanceThe application of ultrasonic assisted extraction (UAE) in food processing technology is of interest for enhancing extraction of components from plant and animal materials. This review shows that UAE technology can potentially enhance extraction of components such as polyphenolics, anthocyanins, aromatic compounds, polysaccharides, oils and functional compounds when used as a pre-treatment step in a unit process. The higher yield obtained in these UAE processes are of major interest from an industrial point of view, since the technology is an “add on” step to the existing process with minimum alteration, application in aqueous extraction where organic solvents can be replaced with generally recognised as safe (GRAS) solvents, reduction in solvent usage, and shortening the extraction time. The use of ultrasonic for extraction purposes in high-cost raw materials is an economical alternative to traditional extraction processes, which is an industry demand for a sustainable development.