Preparation of marine silage of swordfish, ray and shark visceral waste by lactic acid bacteria

Abstract

a b s t r a c tThe goal of the present work was to study the efficacy of several lactic acid bacteria (LAB) as bio-silage inoculants of swordfish, ray and shark viscera by-products. A sterilised medium was initially used as a model system for assessing the potential of these microorganisms in batch and fed-batch cultures with re-neutralisation. In all cases, batch cultivations without re-neutralisation led to the highest production and yields of the main metabolites of LAB fermentation (lactic and acetic acids). The dynamics of these metabolites followed a conversion pattern from lactic to acetic acid with a final joint concentration over 16 g/L and final pH lower than 4.5. Both productions were modelled by means of logistic modified equations. In addition, the capability of LAB to ferment the fish visceral wastes was always high and easily reproducible. Finally, the results obtained for non-sterilised fermentations with Lactobacillus casei CECT 4043 were similar to those obtained for sterilised media, and a stable material was obtained after 72 h of culture.

Valorisation of effluents obtained from chemical and enzymatic chitin production of Illex argentinus pen by-products as nutrient supplements for various bacterial fermentations

“…L. plantarum (Lb 2) and L. casei (Lb 1) were selected for this approach since they have proved to have excellent technological properties including probiotic characteristics [25,26] and fermentation starters ability [11,27,28]. As an example, the complete results of Lb 2 in alternative media and MRS are represented in Figure 3.…”

Utilization of marine by-products for the recovery of value-added products

“…It could be used as an ingredient in feed, supplying protein and water in the formulation to obtain the proper density and stability required for use in aquaculture farms (Gill, 2000). Silage made from whole fish or parts of fish, to which a mineral acid such as formic acid or lactic acid bacteria derived from fermentable carbohydrate substrates are added to lower the pH to below 4.5 (Guérard et al, 2005;Goddard and Perret, 2005;Vázquez et al, 2011). Liquefaction is carried out by endogenous enzymes naturally present in the fish (Guérard et al, 2005;Rai et al, 2011).…”

“…This procedure efficiently prevents the growth of spoilage bacteria (Ghanbari et al, 2013;Tatterson, 1982). After liquefaction, it is convenient to remove the oil coming from the raw material and the protein in the aqueous layer may thereafter be dried or semi-dried (Goddard and Perret, 2005;Vázquez et al, 2011). The main advantages of fish silage are the recovery of fish offal and waste fish, low cost, good nutritional value of the resulting product is its long storage life.…”

Chondroitin Sulfate, Hyaluronic Acid and Chitin/Chitosan Production Using Marine Waste Sources: Characteristics, Applications and Eco-Friendly Processes: A Review

“…The production of bio-silages from fish by-products consists on the ability of LAB strains to ferment the waste materials and to produce in situ organic acids, mainly lactic and acetic acids, in order to preserve and produce ingredients for animal feed production [18,102]. This methodology has also been applied for the recovery of other value-added by-products from ensilaged shrimp waste, such as carotenoids [143].…”

“…, from skeletons, skins, viscera, heads, etc. [8,9,10,11,12,13,14,15,16,17,18,19,20,21,22]. Bearing in mind the number of applications and the economical value of final products, glycosaminoglycans and chitin are two of the most important and relevant compounds to upgrade from marine wastes [23].…”