Special Issue Editor

Dr. Dimitris P. Makris

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Guest Editor

Department of Food Technology, University of Applied Sciences of Thessaly, Karditsa–43100, Greece
Interests: food and beverage polyphenols; polyphenol extraction; valorization of beverage industry waste; natural antioxidants

Special Issue Information

Dear Colleagues,

Waste prevention is a top priority in waste policy in numerous countries around the globe and includes every action in the direction of waste reduction, to avoid negative environmental impact. Agri-food production is an industrial sector that generates large volumes of various wastes, which are hazardous materials. If they are not properly handled and disposed of, and they are typically characterised by exceptionally high levels of chemical oxygen demand (COD). As conventional treatments of agri-food industry wastes for safe discharge are thought to be expensive, laborious, and energy-demanding, there is an increasing need for reuse and recycling, with the aim of recovering precious chemicals, within a general framework of biorefinery. Agri-food solid processing residues are characterised by a high burden in functional phytochemicals, which are secondary plant metabolites with potential health benefits, attributed to their antioxidant activity, and also the antimicrobial, antiviral, and anti-inflammatory effects. Hence, this waste material is regarded as a low-cost resource for the recovery of substances, which may have a significant prospect as pharmaceuticals, cosmetic constituents, food additives and nutritional supplements. This perspective has led to an increasing interest on the development of sustainable tools and methodologies for the effective valorisation of agri-food wastes. On such a conceptual background, it is proposed that this special issue be devoted to state-of-the-art strategies of food waste reuse and prevention, with particular emphasis being given on the development of cutting-edge methodologies related with bioactive compound recovery and their uses in food, pharmaceutical and cosmetics industries.

Dr. Dimitris P. Makris
Guest Editor

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Keywords

Food waste valorization
Bioactive substances
Recovery and reuse

Published Papers (3 papers)

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Research

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15 pages, 1171 KiB

Open AccessArticle

A Green Extraction Process to Recover Polyphenols from Byproducts of Hemp Oil Processing

by Ioannis Mourtzinos, Nikolaos Menexis, Dimitrios Iakovidis, Dimitris P. Makris and Athanasia Goula

Recycling 2018, 3(2), 15; https://doi.org/10.3390/recycling3020015 - 22 Apr 2018

Cited by 16 | Viewed by 5747

Abstract

The valorization of solid waste hemp (Cannabis sativa L.) by a non-conventional method is presented in this article. Hemp polyphenols were extracted using aqueous solutions of 2-hydroxypropyl-β-cyclodextrin as an eco-friendly extraction solvent. Cyclodextrins (CD’s) are known to enhance the extraction of polyphenols in water by forming water soluble inclusion complexes. The process was optimized by implementing a response surface methodology (RSM) that took into consideration the following independent variables: CD concentration (CCD), solid-to-liquid ratio (S/L), and temperature (T). The assessment of the extraction model was based on two responses: the total polyphenol yield (YTP) and the antiradical activity (AAR). The optimum operating conditions were found to be: CD concentration, 32.1% (w/v); solid/solvent ratio, 1/15.2 g/mL; and extraction temperature, 28 °C. Different kinetic models were employed to fit with experimental data and the Peleg’s model was successfully developed for describing the mechanism of extraction under different processing parameters. Full article

(This article belongs to the Special Issue Food Waste – Strategies to Reuse and Prevention)

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12 pages, 589 KiB

Open AccessArticle

Upgrading of Mixed Food Industry Side-Streams by Solid-State Fermentation with P. ostreatus

by Theodoros Aggelopoulos, Argyro Bekatorou, Stavros Plessas, Athanasios A. Koutinas and Poonam Nigam

Recycling 2018, 3(2), 12; https://doi.org/10.3390/recycling3020012 - 01 Apr 2018

Cited by 7 | Viewed by 4373

Abstract

In the frame of efforts to exploit agroindustrial side-streams and wastes (AISS) for added-value products that are based on single cell protein (SCP), mixed substrates consisting of brewer’s spent grains (BSG), malt spent rootlets (MSR), cheese whey, molasses, orange, and potato pulps, were used for growth of the edible mushroom Pleurotus ostreatus. The substrates were mixed in various combinations, and were used for P. ostreatus growth at various conditions. The substrate, for which the highest sugar consumption, protein increase, and mycelium yield were observed, consisted of 20 mL molasses (4° Baume density), 20 mL potato pulp, 5 mL whey, 5 mL orange pulp, 30 g BSG, and 5 g MSR (at 25 °C and substrate pH 4). The mycelium-enriched product was analyzed for protein, fat, minerals (Ca, Mg, Fe, Cu), and aroma volatile compounds, indicating the potential for use as nutritious supplement for food, feed, or microbiology uses. The product was also autolyzed, freeze-dried, powdered, and analyzed for total ribonucleic acid content, showing the potential for use as a commercial natural food flavor enhancer. Full article

(This article belongs to the Special Issue Food Waste – Strategies to Reuse and Prevention)

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Graphical abstract

Review

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19 pages, 2446 KiB

Open AccessFeature PaperReview

The Potential of Tree Fruit Stone and Seed Wastes in Greece as Sources of Bioactive Ingredients

by Stella A. Ordoudi, Christina Bakirtzi and Maria Z. Tsimidou

Recycling 2018, 3(1), 9; https://doi.org/10.3390/recycling3010009 - 05 Mar 2018

Cited by 27 | Viewed by 8948

Abstract

The inedible part (stones, husks, kernels, seeds) of the tree fruits that are currently processed in various regions of Greece constitutes a huge portion of the fruit processing solid waste that remains underexploited. In this review, the existing scientific background for the composition and content of fruit stone and seed in bioactive ingredients is highlighted for olives, stone fruits and citrus fruits that represent the economically most important tree crop products of the country. The content of bioactive compounds may vary considerably depending on the quality of the raw material and the treatment during processing. However, both the hydrophilic and the lipophilic fractions of the seeds contain significant amounts of the primary and the secondary plant metabolites. Among them, phytosterols and several types of polyphenols, but also squalene, tocopherols and some other terpenoids with a unique structure are of particular importance for the utilization and valorization of stones and seeds. Official and scholar records about the current management practices are also presented to highlight the dynamics of the Greek fruit sector. Prospects for the regionalization of fruit seed wastes, in line with EU-promoted Research and Innovation Strategies (RIS) for Smart Specialization are critically discussed. Full article

(This article belongs to the Special Issue Food Waste – Strategies to Reuse and Prevention)

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