Effects of dietary substitution of fishmeal by black soldier fly (Hermetia illucens) meal on growth performance, whole-body chemical composition, and fatty acid profile of Pontastacus leptodactylus juveniles

Freshwater crayfish are considered as aquatic products of high quality and high nutritional value. The increasing demand has led to populations reduction in several locations throughout their range. Thus, the development of appropriate rearing conditions is considered necessary, among which, optimization of their diet is a basic part. Towards this direction, in the present study, a 98-day feeding trial was carried out to evaluate the impact of dietary fishmeal substitution by Hermetia illucens meal on Pontastacus leptodactylus juveniles kept under laboratory conditions. Insect meals represent an environmentally friendly alternative solution, considered as a high-value feed source, rich in nutrients such as protein and fat. Three dietary regimens were utilized with a fishmeal-based without Hermetia meal (HM) defined as the control diet (HM0), and two diets, the first with 50% (HM50) and the second with 100% (HM100) of fishmeal substitution by HM, respectively. Growth performance, whole-body composition, and fatty acid profiles of individuals were studied in the different treatments. At the end of the feeding trial, statistically significant differences were observed in the mean survival rate (SR), specific growth rate (SGR), feed conversion ratio (FCR) and weight gain (WG) values. More specifically, animals fed with HM-based diets had higher mean SR, while the control group performed better regarding FCR and SGR. The HM inclusion in the diet significantly altered the whole-body chemical composition of the crayfish signifying a different metabolic utilization compared to fishmeal (FM). The fatty acid analysis revealed that 16:0 (palmitic acid) was the predominant saturated fatty acid (SFA), 18:1ω9 (oleic acid) was found to be the main monounsaturated fatty acid (MUFA), while 18:2ω6 (linoleic acid) represented the major polyunsaturated fatty acid (PUFA) followed by C20:3 cis ω3 (cis-11-14-17-eicosatrienoate) and C22:6 cis ω3 (cis-4,7,10,13,16,19-Docosahexaenoic) fatty acids. The inclusion of dietary HM significantly reduced the contents of ∑SFAs, ∑PUFAs and ∑ω6 fatty acids, as well as those of C22:6 cis ω3 and increased the ω6/ω3 and hypocholesterolemic to hypercholesterolemic ratios in the body. In parallel with improvements in balanced diets and in culture conditions that need to be optimised for rearing of freshwater crayfish, our study provides new data that enlighten the suitability of insect meals in the nutrition of P. leptodactylus

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

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

Green Extraction Technology of Polyphenols from Food By-Products

The development of environmentally friendly approaches to produce high-added value compounds is a field of research that has attracted the interest of the scientific community and several industries such as the food and cosmetic industry [...

Comparison of qualitative characteristics of propolis extracts using different purification methods

Purification of extracts is an essential procedure in order to remove wax and other undesirable ingredients while retaining the polyphenolic fraction which contains most of bioactive components. This study investigates how different purification methods affect the qualitative characteristics of propolis extracts. Five different purification methods were conducted both for ethanolic and methanolic extracts: (a) centrifugation for 30 min at 370 g; (b) centrifugation at −5 °C for 10 min at 1850 g twice with a 15 min interval; (c) centrifugation at 3340 g for 2.5 min twice with a 15 min interval; (d) filtration through a 0.22 μm polyethersulfone membrane; (e) filtration through a 0.45 μm pore size nylon membrane filter using Buchner vacuum system. Methods were evaluated with reference to the post-treatment antioxidant activity (radical scavenging), total phenolic content and total flavonoid content of each extract. Two different methods of centrifugation were found to be the most effective and stable: centrifugation at 3340 g for 2.5 min or for 10 min at 1850 g, at −5 °C

Hydrogels, Oleogels and Bigels as Edible Coatings of Sardine Fillets and Delivery Systems of Rosemary Extract

Edible coatings provide an alternative way to reduce packaging requirements and extend the shelf life of foods by delaying oxidation and microbial spoilage. Hydrogels, oleogels and bigels were applied as coatings on fresh sardine fillets. The effectiveness of these coatings as delivery systems of rosemary extract (RE) was also evaluated. Three groups of sardine fillet treatments were prepared: (i) the control (C), which comprised sardine fillets without coating, (ii) sardine fillets with plain hydrogel (H), oleogel (O) or bigel (BG) coatings, and (iii) sardine fillets with RE incorporated into the H, O and BG coatings. The different treatments were evaluated for lipid oxidation (TBA test), total volatile basic nitrogen (TVB-N) and microbiological growth during cold storage at 4 °C. Results showed that hydrogel, oleogel and bigel coatings delayed oxidation. The incorporation of RE into coatings significantly retarded lipid oxidation but did not affect the proliferation of microorganisms during storage. When RE was incorporated in the oleogel phase of the bigel coating, it produced significantly lower TVB-N values compared to the control and BG treatments. The incorporation of RE into the oleogel phase of the bigel coating may be a promising method of maintaining the storage quality of the sardine fillets stored at refrigerated temperatures

Innovative Delivery Systems Loaded with Plant Bioactive Ingredients: Formulation Approaches and Applications

Plants constitute a rich source of diverse classes of valuable phytochemicals (e.g., phenolic acids, flavonoids, carotenoids, alkaloids) with proven biological activity (e.g., antioxidant, anti-inflammatory, antimicrobial, etc.). However, factors such as low stability, poor solubility and bioavailability limit their food, cosmetics and pharmaceutical applications. In this regard, a wide range of delivery systems have been developed to increase the stability of plant-derived bioactive compounds upon processing, storage or under gastrointestinal digestion conditions, to enhance their solubility, to mask undesirable flavors as well as to efficiently deliver them to the target tissues where they can exert their biological activity and promote human health. In the present review, the latest advances regarding the design of innovative delivery systems for pure plant bioactive compounds, extracts or essential oils, in order to overcome the above-mentioned challenges, are presented. Moreover, a broad spectrum of applications along with future trends are critically discussed

An Eco-Friendly Supercritical CO₂ Recovery of Value-Added Extracts from <i>Olea europaea</i> Leaves

An eco-friendly approach towards the recovery of value-added extracts from olive tree leaves with the aid of supercritical CO2 at 30 MPa was carried out. The impact of extraction temperature (35–90 °C) and presence of co-solvents (ethanol, water, and aqueous ethanol) on the total phenolic, flavonoid, and pigment content, as well as oleuropein, hydroxytyrosol, tyrosol, and α-tocopherol content was determined. In addition, the antioxidant activity of extracts from tree leaves using DPPH, ABTS, and CUPRAC assays was investigated. The results of the study showed that the most effective supercritical CO2 extraction was at 90 °C with an addition of ethanol, which enabled the separation of extract with the highest content of tested compounds. Some of the highest recorded values were for oleuropein 1.9 mg/g, for carotenoids 5.3 mg/g, and for α-tocopherol 2.0 mg/g. Our results are expected to contribute to the efforts towards the valorization of olive leaves as a sustainable source of valuable compounds, and boost local economies as well as the interest of pharmaceutical, food, and cosmetic industries for novel food by-product applications

Optimization of a Green Extraction/Inclusion Complex Formation Process to Recover Antioxidant Polyphenols from Oak Acorn Husks (Quercus Robur) Using Aqueous 2-Hydroxypropyl-β-Cyclodextrin/Glycerol Mixtures

Aqueous mixtures of glycerol and 2-hydroxypropyl-β-cyclodextrin (CD), two non-toxic eco-friendly substances, were used as a means of extracting antioxidant polyphenols from oak acorn (Quercur robur) husks. The process was optimized by implementing a central composite (Box-Behnken) experimental design and response surface methodology, taking into consideration the critical parameters (independent variables) of glycerol concentration (Cgl), CD concentration (CCD) and temperature (T). The assessment of the extraction model was based on three responses: the total polyphenol yield (YTP), the antiradical activity (AAR) and the reducing power (PR). The model illustrated that YTP depended significantly on Cgl and CCD, but not on T, whereas both antioxidant properties considered (AAR and PR) were temperature-dependent. The maximum predicted YTP was 122.19 mg GAE per g dry husk weight, while the extract obtained under optimized conditions displayed strong antioxidant activity