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.     

Utilization of Fish Processing By-Products in the Gelatin Industry

Since the bovine spongiform encephalopathy crisis, there has been a growing interest for finding an alternative source of raw materials for gelatin production. Gelatin produced from fish processing by-products is a potential alternative to mammalian gelatin. Fish processing generates solid wastes that can be as high as 50-80% of the original raw material. These wastes are an excellent raw material for preparation of high protein foods. About 30% of the wastes consists of skin and bone with a high collagen content. Fish gelatin can be obtained by hydrolysis of collagen the principal protein found in skin and bone. Fish skin and bone gelatin can be prepared with bloom strength similar to that obtained from mammalian sources. Fish gelatin has numerous applications, particularly, in the food, pharmaceutical, and photographic industries due to its unique chemical and physical properties. This review presents how fish processing by-products can be utilized in the manufacture of gelatin.     

Utilization of Fish Processing By-Products in the Gelatin Industry

Since the bovine spongiform encephalopathy crisis, there has been a growing interest for finding an alternative source of raw materials for gelatin production. Gelatin produced from fish processing by-products is a potential alternative to mammalian gelatin. Fish processing generates solid wastes that can be as high as 50–80% of the original raw material. These wastes are an excellent raw material for preparation of high protein foods. About 30% of the wastes consists of skin and bone with a high collagen content. Fish gelatin can be obtained by hydrolysis of collagen the principal protein found in skin and bone. Fish skin and bone gelatin can be prepared with bloom strength similar to that obtained from mammalian sources. Fish gelatin has numerous applications, particularly, in the food, pharmaceutical, and photographic industries due to its unique chemical and physical properties. This review presents how fish processing by-products can be utilized in the manufacture of gelatin.     

Current applications and new opportunities for the use of pulsed electric fields in food science and industry

Several studies have demonstrated the feasibility of pulsed electric fields (PEF) for different applications in food industry. PEF technology is therefore a valuable tool that can improve functionality, extractability, and recovery of nutritionally valuable compounds as well as the bioavailability of micronutrients and components in a diverse variety of foods. Additionally, other studies have shown the potential of PEF treatments to reduce food processing contaminants and pesticides. This opens the doors to new PEF applications in the food industry. This review focused on some of the most renowned traditional and emerging PEF applications for improvement of osmotic dehydration, extraction by solvent diffusion, or by pressing, as well as drying and freezing processes. The impact of PEF on different products of biological origin including plant tissues, suspension of cells, by-products and wastes will be analyzed in detail. In addition, recent examples of PEF-assisted biorefinery application will be presented, and finally, the main aspects of PEF-assisted cold pasteurization of liquid foods will also be described.     

Bioactive compounds from marine processing byproducts – A review

Generation of immense quantity of underutilized marine processing byproducts has long been recognized as wastes and greater efforts were given to use these materials in various applications. With a great number of researches on these byproducts, some biologically active compounds were identified and applicated to the useful compounds for human utilization. Potential applications of proteins, lipids, chitin and minerals in marine bioprocessing leftovers as bioactive materials have increased the value of processing byproducts in recent years. In this review, we have focused on the utilization of marine processing byproducts to screen bioactive compounds and their potential applications.     

Therapeutic and Nutraceutical Potential of Bioactive Compounds Extracted from Fruit Residues

The growing interest in the substitution of synthetic food antioxidants by natural ones has fostered research in identifying new low-cost antioxidants having commercial potential. Fruits such as mango, banana, and those belonging to the citrus family leave behind a substantial amount of residues in the form of peels, pulp, seeds, and stones. Due to lack of infrastructure to handle a huge quantity of available biomass, lack of processing facilities, and high processing cost, these residues represent a major disposal problem, especially in developing countries. Because of the presence of phenolic compounds, which impart nutraceutical properties to fruit residues, such residues hold tremendous potential in food, pharmaceutical, and cosmetic industries. The biological properties such as anticarcinogenicity, antimutagenicity, antiallergenicity, and antiageing activity have been reported for both natural as well as synthetic antioxidants. Special attention is focused on extraction of bioactive compounds from inexpensive or residual sources. The purpose of this review is to characterize different phenolics present in the fruit residues, discuss the antioxidant potential of such residues and the assays used in determination of antioxidant properties, discuss various methods for efficient extraction of the bioactive compounds, and highlight the importance of fruit residues as potential nutraceutical resources and biopreservatives.     

Integrated processing of plant-derived waste to produce value-added products based on the biorefinery concept

BackgroundPlant-derived wastes from agriculture, processing, distribution, and retail are generated in large quantities. The majority of the wastes are underutilized and may cause severe environmental problems if not properly handled. The plant-derived wastes are usually rich in lignocellulose and other valuable compounds including protein, fat, sugar, and phytochemicals. Valorization of these compounds in food waste not only reduces environmental concerns but also improves sustainability and economic competitiveness of agro-food industries.Scope and approachThis review paper first discussed different phases of the biorefinery concepts and their associated applications, and then introduced recent advances in the integrated processing of plant-derived waste for producing various value-added products. Finally, techno-economic, environmental, and social assessments along with relevant policies were introduced and discussed.Key findings and conclusionsDuring the past ten years, research attentions focused on integrated utilization of plant-derived waste to produce various products have flourished. Compared to production of a single component for food waste valorization, integrated processing of food waste via a combination of different novel technologies to produce multiple products based on a biorefinery concept has significant advantages, including full utilization of feedstocks, minimization of waste generation during processing, synergy effects of different technologies, and diversification of the revenues by covering multiple markets. With the rationale design of biorefinery processes, underutilized plant-based wastes can be valuable resources for the sustainable production of food, chemicals, and biofuels. However, detailed economic, environmental, and social analyses for the biorefinery process are still needed in the future.     

Brewers' spent grain: a review with an emphasis on food and health

Brewers' spent grain (BSG) is the most abundant by‐product generated in the beer‐brewing process. This material consists of the barley grain husks obtained as solid residue after the production of wort. BSG is rich in fibre and protein and, to date, the main use for the elimination of this by‐product has been as an animal feed. However, because of its nutritional content, BSG is of interest for application and fortification of human food products, particularly in view of its low cost and availability in large amounts. In addition, the importance of BSG as an ingredient and potential source of health‐promoting bioactive components is beginning to be recognised. The investigation of alternative uses of BSG is pertinent, not only from the perspective of the brewer who can benefit from valorisation of this by‐product, but also from an environmental perspective as the recycling and re‐use of industrial wastes and by‐products has become increasingly important. This review presents the current knowledge on BSG, covering its production, composition and methods for the release of valuable components, and focuses on the potential health benefits attributed to its constituents and the use of this brewer by‐product in food applications. Copyright © 2016 The Institute of Brewing & Distilling     

Enzymes in fish processing,biosensors and quality control: A review

Abstract

A number of enzymes have uses in fish processing and quality control. Then‐applications may be broadly grouped into: modifications of proteins, enrichment of polyuasaturated fatty acids (PUFA) in lipids, shelf life extension, and as components of biosensors and also in direct assays for quality evaluation of fishery products. Protein processing using proteases include preparation of protein hydrolysates, debittering of protein hydrolysates, removal of scales from some fish species, recovery of proteins from filleting wastes, roe processing, extraction of flavours, carotenoids and other ingredients from fish waste etc. The importance of PUFA in health care has encouraged processes for enrichment of fats and oils using lipases. Glucose oxidase, catalase, and rysozyme have shown potential as food additives for preservation of fish quality. Apart from their role in process developments, a number of enzymes may also be used as components of biosensor systems for rapid evaluation of fish quality. Many of these enzymes may also be extracted from fish wastes generated during commercial fish processing. Recovery of such enzymes from the waste serves the dual purposes of waste disposal as well as providing novel tools for fish processing. This article summarises the status in the field.     

利用马铃薯淀粉生产的废水及废渣发酵制备蛋白饲料

以马铃薯淀粉生产的废水及废渣为原料,采用微生物发酵的方法,制备高附加值的蛋白饲料,同时降低废水的COD值,达到综合利用的目的。经试验筛选得到1株酵母,并确定了蛋白饲料的制备条件:废水中薯渣添加量20%、pH自然、温度28℃、接种量10%、发酵时间72 h。在适宜条件下,制备的蛋白饲料蛋白含量达37.40%,废水COD降低72.29%。     

Characterisation of processing wastes of Atlantic Salmon (Salmo salar) and Yellowtail Kingfish (Seriola lalandi) harvested in Australia

Atlantic Salmon (AS) and Yellowtail Kingfish (YTK) are two major commercial fish species in Australia. During food processing, waste material of 40–50% of the whole AS and YTK is generated, including the head, skin, frame, belly flap and viscera. This material is usually discarded even though it is rich in protein and fat. The aim of this study was to characterise the composition of these wastes for their potential applications. The contents of protein and fat in these wastes are 10–20% and 20–30%, respectively. Profiles of amino acids, fatty acids and minerals showed they are good sources of essential amino acids (20–30% of total amino acids), omega‐3 fatty acids (about 20% of total fatty acids) and various elements. For example, AS viscera is high in zinc (740 mg kg^?1). Molecular weight distribution of the protein was mainly between 25 and 250 kDa. The potential commercial applications of these wastes are discussed on the basis of these analyses.     

Proximal composition,bioactive compounds and biorefinery approach in potato tubers of Solanum tuberosum Group Phureja: a review

Potato tubers of Group Phureja have a great relevance in terms of production and consumer acceptance in the Andean countries. However, its proximal characteristics, nutritional value and bioactive compounds have been scarcely known. For the first time, this work aims to give an overview on tubers of Group Phureja characteristics, including research works from 1993 to 2019. When analysing the micronutrients and bioactive analytes, sodium, niacin and carotenoid contents are higher as compared to those of the Group Tuberosum. Likewise, the application of a biorefinery approach for the valorisation of Group Phureja wastes was proposed. These wastes may come from tubers that fail to meet quality parameters or by processing potato products. The possibility of obtaining useful compounds for the food, feed, materials, energy and chemical industries is described. The strategy of valorisation of wastes was focused on the production of starch and proteins, previously reported with important technological properties.     

Antioxidant properties of various solvent extracts of potato peel,sugar beet pulp and sesame cake

BACKGROUND: Growing interest in the replacement of synthetic food antioxidants by natural ones has fostered research on vegetable sources and screening of raw materials to identify new antioxidants. The food‐processing industry generates substantial quantities of phenolic‐rich by‐products that could be valuable natural sources of antioxidants. In this study the antioxidant properties and total phenolic, flavonoid and flavonol contents of three industrial by‐products, sugar beet pulp, sesame cake and potato peel, extracted with various solvents were examined. Since different antioxidant compounds have different mechanisms of action, several methods were used to assess the antioxidant efficacy of extracts. RESULTS: Among the six solvents tested, methanol gave the highest extract yield of potato peel and sugar beet pulp, while diethyl ether gave the highest extract yield of sesame cake. Methanol exhibited the highest extraction ability for phenolic compounds, with total phenolics amounting to 2.91, 1.79 and 0.81 mg gallic acid equivalent g^?1 dry weight in potato peel, sugar beet pulp and sesame cake extracts respectively, and also showed the strongest antioxidant capacity in the three assays used. All three methods proved that potato peel extract had the highest antioxidant activity owing to its high content of phenolic compounds and flavonoids. CONCLUSION: On the basis of the results obtained, potato peel, sugar beet pulp and sesame cake extracts could serve as natural antioxidants owing to their significant antioxidant activity. Therefore they could be used as preservative ingredients in the food and/or pharmaceutical industries. Copyright © 2009 Society of Chemical Industry     

Effect of inoculation of vegetable processing wastes with lactobacillus plantarum on silage fermentation

Small amounts (450 g) of experimental silages were prepared from green beans and potato processing wastes. Green bean wastes were dried or mixed with peanut (groundnut) hulls to reduce the percentage of moisture in the silage. Potatoes were not treated to remove moisture. The effects of inoculating these food processing wastes with Lactobacillus plantarum (5 × 10⁶ g^?1 wet weight) on pH decline, microbial populations and volatile and non-volatile fatty acids were determined. The inoculum decreased pH, increased lactic acid and decreased acetic and other volatile acids in some silages. All silages had high numbers of streptococci initially and this population was succeeded by lactobacilli with higher numbers of the latter microflora observed in inoculated silages. Yeasts, moulds and clostridia were recovered in high numbers only in un-inoculated silages prepared with peanut hulls. Although control silages had pH declines probably adequate for preservation, the bacterial additive had an overall beneficial effect on these fermentations.     

Valorization of pomelo (Citrus grandis Osbeck) peel: A review of current utilization,phytochemistry, bioactivities,and mechanisms of action

Citrus grandis Osbeck, commonly known as “pomelo” or “shaddock,” is the largest citrus fruit, the peel of which is a well‐known agricultural residual waste. Pomelo peel offers a wide range of components such as essential oils, polysaccharides, and phytochemicals with potential food applications. Utilization of pomelo peel to recover these components is an important step toward agricultural sustainability. This review covers pomelo peel utilization opportunities beyond conventional composting and animal feed production, and critically examines value‐added uses via the recovery of potentially bioactive components. The peel of pomelo accounts for approximately 30% of the total fruit weight and contains phytochemicals, including aroma‐active volatiles, pectin, flavonoids, phenolic acids, carotenoids, coumarins, and polysaccharides. Recovery of these phytochemicals offers an opportunity for value‐added utilization such as the development of enriched or functional foods and nutraceuticals. The health‐promoting and therapeutic potential of pomelo peel extracts and isolated pure compounds have been evaluated through numerous in vitro and in vivo studies that revealed a wide range of bioactivities, including hypolipidemic, hypoglycemic, antioxidant, antimicrobial, anti‐inflammatory, and anticancer effects. Preclinical evidence highlights multifaceted molecular and signaling events that possibly underlie the said bioactive potential. Overall, the pomelo processing industry offers a great opportunity to recover or produce valuable products from the large amounts of residual wastes it generates. It is envisaged that a thorough understanding of the bioactive components of pomelo peel, their functional and nutraceutical applications, and mode of actions will benefit the food industry.     

Industrial applications of crustacean by-products (chitin,chitosan, and chitooligosaccharides): A review

BackgroundFood processing produces large quantities of by-products. Disposal of waste can lead to environmental and human health problems, yet often they can be turned into high value, useful products. For example, crustacean shell wastes from shrimp, crab, lobster, and krill contain large amounts of chitin, a polysaccharide that may be extracted after deproteinisation and demineralization of the exoskeletons.Scope and approachThis review summarizes the current state of knowledge of these crustacean shellfish wastes and the various ways to use chitin. This biopolymer and its derivatives, such as chitosan, have many biological activities (e.g., anti-cancer, antioxidant, and immune-enhancing) and can be used in various applications (e.g., medical, cosmetic, food, and textile).Key findings and conclusionsDue to the huge waste produced each year by the shellfish processing industry and the absence of waste management which represent an environmental hazard, the extraction of chitin from crustaceans’ shells may be a solution to minimize the waste and to produce valuable compound which possess biological properties with application in many fields. As a food waste, it is important to also be aware of the non-food uses of these wastes.     

Advances in pullulan production from agro-based wastes by Aureobasidium pullulans and its applications

Pullulan is an important exopolysaccharide commercially obtained from ubiquitous fungi Aureobasidium pullulans. Pullulan has unique physicochemical properties, due to which it has wide applications in the food, pharmaceutical and biomedical industries. Various synthetic media and agro-industrial wastes have been utilized for the production of pullulan. Agro-industrial waste has become a preferred substrate for biotransformation due to its economical aspect and nutritional attributes. Pullulan is one of the valuable products produced by the biotransformation of agro-based wastes. Numerous factors which influence the pullulan production are the type of substrate, the addition of carbon source, nitrogen source, pH of the medium, aeration/ agitation speed and temperature. The cost, productivity of the product and efficiency depends on the selection of raw material, type of fermentation (bioprocess), type of strain and downstream processing (recovery). This review focuses on pullulan production from agro-based wastes, the influence of factors and its applications.     

板栗加工副产物抑菌作用的研究进展

板栗加工过程易产生诸如板栗壳、板栗花、板栗总苞、板栗 次果及次品等副产物,大量资源常被当作废弃物丢弃,未得到有效利用, 开发的产品较少,造成资源浪费。近年来,有关板栗加工副产物的研究得 到关注,板栗中存在的多种天然活性成分相继被报道,其中具有抑菌作用 的成分占比较高。因此,该研究综述了板栗加工副产物含有的抑菌成分 及其作用机理,以期为板栗加工副产物在抑菌材料方面的应用提供一定 的参考。     

Characterization and determination of brewer's solid wastes composition

Agro‐industrial wastes are produced in large quantities around the world from the processing and manufacturing of food and beverages. The disposal of these wastes into the environment leads to damage to ecosystems owing to their composition rich in organic matter. In this context it may be noted that the brewing industry, whose production process includes processing steps and fermentation of vegetable raw materials such as barley and/or other grains used as adjuncts and hops, generates various byproducts. The worldwide consumption of these beverages and the current model of breweries, which includes production on a large scale, lead to the generation of large amounts of brewery waste, namely spent grain, hot trub and residual yeast. Owing to its composition, these residues exhibit significant potential for application in bioprocess technologies. In this study the three residues mentioned had their composition determined as a function of moisture, ash, total organic carbon (TOC), total and soluble nitrogen, reducing sugar and soluble free amino nitrogen. Moreover, the residues were characterized for total acidity, pH and chemical oxygen demand (COD) of total and soluble fractions. The three residues evaluated had high moisture content (>80%) and high organic matter content (TOC and COD, ~50% and >1000 mg/g, respectively), which can highlights the significant protein fraction (almost 50% for hot trub and residual yeast), suggesting the possibility of using these wastes for recovery. Copyright © 2015 The Institute of Brewing & Distilling     

马铃薯淀粉凝胶形成及其品质影响因素研究进展

马铃薯淀粉黏度高、易糊化,淀粉糊稳定性及透明度高,被广泛应用于各类凝胶制品的加工中。温度、pH等环境因素以及盐类、多糖、蛋白质等食用成分对马铃薯淀粉的糊化特性及淀粉凝胶的回生特性、流变特性、微观结构等影响不同,进而影响马铃薯淀粉凝胶制品的品质。本文在分析马铃薯淀粉凝胶形成机制的基础上,综述了不同环境因素及食用成分对马铃薯淀粉凝胶品质特性的影响规律,揭示了不同食用成分与马铃薯淀粉分子之间的相互作用原理。旨在为高品质、高营养马铃薯淀粉凝胶及其制品的研究与工业化生产提供参考。