A huge amount of waste products is being produced by the food processing industries in most countries across the globe. These huge quantities of by-products include pomace, seed, peel, stems, pulp, ...shells, etc. can lead to environmental pollution. Most of these industrial by-products are good sources of dietary, functional, and novel fibres. Nowadays, these dietary fibres are given great attention because of their physiological properties which are essential for human health. These waste products from fruits can further be used for the manufacturing of many functional ingredients.
•The fruits and vegetable by-products are a potent source of dietary fibers.•The dietary fibers find good applications in food.•Dietary fibers possess various functional properties.•There are many health benefits of dietary fibers.
•Review focused on UAE of bioactive compounds from fruit and vegetable by-products.•Summarized the factor affecting the UAE of bioactive compounds.•Frequency of UAE for bioactive compounds lies in ...range of 20–40 kHz.•RSM with numerical optimization is commonly used for optimization of UAE.
Growing fruit and vegetable processing industries generates a huge amount of by-products in the form of seed, skin, pomace, and rind containing a substantial quantity of bioactive compounds such as polysaccharides, polyphenols, carotenoids, and dietary fiber. These processing wastes are considered to be of negligible value compared to the processed fruit or vegetable due to lack of sustainable extraction technique. Conventional extraction has certain limitations in terms of time, energy, and solvent requirements. Ultrasound assisted extraction (UAE) can extract bioactive components in very less time, at low temperature, with lesser energy and solvent requirement. UAE as a non-thermal extraction technique is better equipped to retain the functionality of the bioactive compounds. However, the variables associated with UAE such as frequency, power, duty cycle, temperature, time, solvent type, liquid-solid ratio needs to be understood and optimized for each by-product. This article provides a review of mechanism, concept, factor affecting extraction of bioactive compounds with particular focus on fruit and vegetable by-products.
Aqueous Zn‐ion batteries are emerging as a promising candidate for large‐scale energy storage, while the short lifetime and poor reversibility of Zn anodes limit their further development. When ...attempting to enhance reversibility, most reported methods involve toxic and pollutive substances and decreased water content, which inevitably sacrificed safety level, rate performance, and environmentally benign characteristics. Herein, a series of low‐cost and “green” molecules are introduced into the aqueous (ZnCl2, ZnSO4) electrolytes, featured with cations coordination capability, which can significantly inhibit the hydration step of Zn2+ and delay the formation of the key by‐products (Zn5(OH)8Cl2·H2O, 3Zn(OH)3·ZnSO4·5H2O) in aqueous electrolytes via regulating the coordination status of Zn2+. In the optimized electrolyte system, a highly reversible Zn metal anode presents excellent electrochemical performance, featured with a long lifespan over 1185 h at 1 mA cm−2 and smooth deposition morphology. Furthermore, Zn–MnO2 batteries based on the electrolyte deliver high capacity retention of 82.9% after 200 cycles. These breakthroughs suggest that this method offers a versatile toolbox toward developing future advanced multivalent metal batteries for large‐scale energy storage.
The introduction of electron‐donating substituents can improve the electron‐donating capacity of ligands, a critical factor in the cation coordination process. In this way, the formation of Zn(OH2)62+, which is a key species that leads to the formation of by‐products through dehydrogenation, is well inhibited. This method can improve the efficiency of Zn metal plating/stripping in a water‐abundant electrolyte.
The papers published in this Special Issue report on recent studies investigating the exploitation of by-products produced by the food industry. The topics investigated include the extraction setups ...used for valuable food waste by-products and their applications as adjuncts to food preparation; the appropriate selection of solvents and extraction processes; and the interactions between extracted fractions and supplementary foods. The papers evaluate a wide variety of foodstuffs and provide results regarding the extension their shelf-lives and activities as functional foods.
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•UV/S(IV) system showed selective and efficient decay of ClO2− in potable water.•ClO2− decay was hardly affected by HCO3−, Cl−, SO42−, NO2−, and NO3− in real water.•eaq− and SO3•− ...were identified as the dominant reactive species in this system.•eaq− initiated efficient ClO2− decay, while SO3•− played a role in its selective removal.•Pathways of ClO2− reduction in UV/S(IV) system were proposed accordingly.
Sulfite radicals-based advanced reduction processes (ARPs) have shown promise for efficiently removing chlorite, a toxic by-product of chlorinedioxide disinfection. However, the role of sulfite radicals in chlorite reduction through UV-mediated ARPs has been underestimated, as overshadowed by the superior reductive abilities of hydrated electrons. In this study, we investigated the contributions of sulfite radicals and hydrated electrons in the UV/sulfite (UV/S(IV)) system for chlorite reduction. UV/S(IV) system achieved a nearly complete reduction of 13.5 mg/L chlorite to chloride within 60 min in deionized water using 160 mg/L S(IV) and UV doses of 6.0 mW/cm2. The first-order rate constant for chlorite removal in this system was 0.080 ± 0.006 min−1, up to 27 times faster than in previous systems. In addition, hydrated electrons and sulfite radicals were identified as the dominant reducing species, mainly based on the EPR spectra and results of nitrate/nitrite quenching experiments. Kinetic simulations revealed that short-lived hydrated electrons initiated efficient chlorite reduction, while stable sulfite radicals selectively decomposed chlorite into chloride in complex water matrices throughout the process. Moreover, UV/S(IV) system showed the potential for selectively reducing chlorite to chloride in real water, with > 81.0 % removal of 1.35 mg/L in 60 min. Importantly, this reduction process was hardly influenced by the presence of coexisting water constituents such as HCO3−, SO42−, Cl−, NO3−, and NO2−. This work brightens an overlooked route to selective reduction of chlorite to chloride in UV/S(IV) system.
•BAC efficiency in DBP precursors removal decreased with service life increasing.•DBAN was the dominant driver of toxicity, followed by BCAN and then DCAN.•Young BAC was prone to remove N-DBP than ...C-DBP precursors but reverse for old BAC.•More replacement of filter media by new GAC led to higher DBP precursors removal.
Biological activated carbon (BAC) process is commonly used for drinking water treatment. Granular activated carbon (GAC) serving as the initial filter media can be converted to BAC with biofilm development during extending service life. Consequently, GAC/BAC effectiveness for disinfection by-product (DBP) precursors removal varies over service life. Effluents of full-scale ozonation and BACs operated for 1–3 months (1-month GAC), 4–6 months (4-month BAC), and about 7 years (7-year BAC) were analyzed. All BACs were efficient in fluorescence components removal, with decreasing efficiency in the order of 1-month GAC > 4-month BAC > 7-year BAC. Accordingly, reduction ratios of total DBPs concentration formed in post-chlorination dropped from 39% to 21% and 8% by BACs with different ages. Due to varied toxic potencies of DBPs, toxicities reduction was not completely related to DBPs concentration reduction. Haloacetonitriles (HANs) group accounted for small proportion of DBPs concentration but drove both of cytotoxicity and genotoxicity. Hence, the precursor removals of carbonaceous (C-) DBPs and nitrogenous (N-) DBPs were further compared in detail. 1-month GAC exhibited relatively higher effectiveness for protein-like components removal than humic-like component removal, for HANs formation reduction than trihalomethanes (THMs) formation reduction, and for HANs cytotoxicity reduction than THMs cytotoxicity reduction. A similar pattern was observed for 4-month BAC, while 7-year BAC exhibited the opposite pattern. Given the complexity of real water, this full-scale study provides valuable insights into the differences in precursor removals of C-DBPs and N-DBPs by BACs with different ages, which is critical for advancing our understanding of BAC process.
We investigated semiquantitative changes in almost 1000 dissolved organic matter (DOM) features during oxidation with 1 mg of O3 per liter (mg O3/L), 4 mg O3/L, or 4 mg O3/L + 2.5 mg of H2O2 per ...liter (advanced oxidation process, AOP) by unknown screening analysis with Orbitrap mass spectrometry. The consequential effects on formation of unknown disinfection by-products (DBPs) by chlorination were evaluated in laboratory-scale experiments. Several hundred unsaturated DOM features with positive oxygen-subtracted double bond equivalents per carbon ((DBE–O)/C) were decomposed by the ozone-only treatment and AOP. The AOP decomposed some saturated (negative (DBE–O)/C)) and reduced molecules, which had negative carbon oxidation states (Cos). Several hundred saturated oxidation by-products were detected after ozonation and the AOP. After chlorination, the samples pre-treated with ozone alone resulted in higher formation of unknown DBPs than the AOP pre-treated sample or the sample without oxidation. Over half of the DBP precursors, estimated by electrophilic substitution, were not totally decomposed by any oxidation process, but they were increased after the ozone-only process and AOP. DBP precursors produced by the ozone-only process or AOP formed unique unknown DBPs. Therefore, post-treatment processes after oxidation and before chlorination are important to minimize formation of unknown DBPs.
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•Changes of over 1000 DOM features by ozonation and peroxone were investigated.•Unsaturated DOM features were selectively decomposed by ozone and peroxone.•Several hundred of saturated oxidation byproducts were detected after ozonation and peroxone.•Ozone results in formation of unknown disinfection by-products more than peroxone.•Ozone and peroxone increase generate their specific unknown DBP precursors.
•Saffron global production is estimated at 418 t y−1 on 121,338 ha.•Stigma yield, depending on many factors, ranges between 2 and 28 kg ha−1.•Saffron is suitable for low-input and sustainable ...cropping systems.•New research focuses on the improvement of stigma yield and quality.•Valorisation of saffron by-products can increase the profitability of the spice.
Saffron is obtained from the dried red stigmas of Crocus sativus L., an autumnal herbaceous flowering plant belonging to the Iridaceae family. It is largely cultivated in Iran, India, Afghanistan, Greece, Morocco, Spain and Italy. Saffron global production is estimated at 418 t y−1 on 121,338 ha. It is known as the most expensive spice in the world and as beneficial for human health due to three main bioactive compounds: crocin, picrocrocin and safranal. The demand for saffron is increasing worldwide for its interesting role in cuisine, medicine and cosmetics. Due to the reduction of its production, recent investigations have been conducted to study how to improve stigma yield, quality and antioxidant activity by selecting of corm geographical origin and climatic conditions, using biostimulants such as mycorrhizal fungi as well as choosing irrigation regimes, drying methods and storage processes. New research activities have been focused on the medicinal properties of this spice, such as its neuroprotection in the context of ocular disease, free radical scavenging and detoxifying capacities. This work offers an overview of the historical, economic, genetic, botanical, agronomic and qualitative traits of saffron as well as the properties, traditional and recent uses of the spice as well as its by-products such as tepals, stamens, styles, corms and leaves.
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