Sustainable use of marine resources – turning waste into food ingredients

Abstract

Fish by-products are considered low value and discarded. With proper handling and processing, fish by-products may provide high nutritional value to consumers. This study aimed at establishing compositional differences in valuable compounds from fish by-products of selected species, including Salmon, Flathead, Silver warehou and Barramundi. Simple extraction methods were employed, and obtained fractions were analysed for their chemical and physical properties. The chemical composition of four fish species differed significantly (P < 0.05) with the protein content ranging from 14.7 AE 0.09 to 16.8 AE 0.41%. Adjusting pH to 2.5 yielded two times more of extracted oil than at pH 4.5. Salmon and Barramundi oils contained high amounts of monounsaturated fatty acids (MUFAs) (39-50%), while Silver warehou and Flathead oils contained 46-49% of saturated fatty acids (SFAs). The particle size of the protein fractions was small, ranging from 126.9 to 489.5 nm. Molecular weight of extracted proteins was fish species dependant -Silver warehou and Barramundi samples contained proteins of 250, 120 and 100 kDa, while these bands were absent from Salmon and Flathead samples. The data obtained indicate that extracted fractions from fish by-products likely have high nutritional value and could find a potential use in food formulations.

Valorization of Aquaculture By-Products of Salmonids to Produce Enzymatic Hydrolysates: Process Optimization, Chemical Characterization and Evaluation of Bioactives

“…or other presentations that require deheading, gutting, and filleting steps. Thus, huge amounts of by-products (about 35-45% of the total weight of salmonids) are generated in processing plants, mainly heads, trimmings, viscera, and frames that have to be managed efficiently to reduce environmental health problems and to improve the sustainability of such farming productions [2,3].The most habitual utilization of salmonid wastes is based on the development of acid silage [3], fertilizers, or the joint production of fishmeal and oils [4,5]. In the first case, the silage is a low-added value product with limited applications [1].…”

“…Enzymatic hydrolysis of fish wastes involves a highly controllable and reproducible method for the separation of bones, oils, and peptide fractions from complex matrices. Several fish species, including from farm origin, employing different proteases and conditions of hydrolysis have been studied in the last two decades [2,[8][9][10]. The functional capacity of FPHs in terms of antihypertensive, antioxidant, antiproliferative, antimicrobial, etc., in vitro bioactivities, is one of the most valuable properties of these bioproduction [11][12][13][14].…”

“…or other presentations that require deheading, gutting, and filleting steps. Thus, huge amounts of by-products (about 35-45% of the total weight of salmonids) are generated in processing plants, mainly heads, trimmings, viscera, and frames that have to be managed efficiently to reduce environmental health problems and to improve the sustainability of such farming productions [2,3].…”

Recovery of cathepsins from marinating brine waste

“…During the marinating process, high quantities of the nitrogen via biologically active proteins, peptides and amino acids diffuse from fish tissue into the brine (Szymczak, 2011;. Hence, there is an increasing interest in their recovery and application (Rustad et al, 2011;Gringer et al, 2014Gringer et al, , 2016Nurdiani et al, 2015;Szymczak et al, 2015). Recent studies indicate the marinating brine also includes active aspartyl and cysteine cathepsinsmainly B, D, E and L (Szymczak, 2016a;Szymczak & Lepczy nski, 2016).…”

Sustainable use of silver warehou (Seriollela punctata): effects of storage, processing conditions and simulated gastrointestinal digestion on selected in-vitro bioactivities

“…Interestingly, fish waste, an excellent source of proteins, can be converted into more marketable, functional and health value-added products by novel enzymatic hydrolytic technology (Nurdiani et al 2015). Enzymatic hydrolysis has been widely used to improve the functional properties (water-holding, emulsification, gelling and solubility) of mainly myofibrillar proteins (Kristinsson and Rasco 2000).…”