Valorization of By-Products from Commercial Tuna Cannery for New Formulation of Pet’s Food Product: Physicochemical Characterization and DLC Determination from Commercial for New

Over the past five decades, world fish production has
progressively increased and the amount of fish for consumption has
increased with an average annual growth rate...


ISSN: 2574 -1241 of Tuna; Wet Pet Foods; Expiration Date
Tunisia has natural resources favorable to fishing with a coastline that extends for a total length of 1,300 kilometers. The large quantities processed show that tuna canneries generate an important amount of discarded high-quality species. These wastes are, of course, problems, but they also offer excellent opportunities for biotechnological exploitation. The disposal of these wastes has always been expansive and has often a harmful impact on the environment, but thanks to the evolution of techniques and the development of markets, it is now possible to transform this waste stream into useful and marketable products. Thanks to their high protein content, tuna discarded products represent an important source for the development of a new animal feed product, including the young dog. In the present work, we focused primary on the characterization of the red muscles of a tuna cannery for inclusion in the formulation of young dog's wet food. The composition of these co-products indicates a high protein content (80%), and a moderate fat and mineral content (11% and 8%, respectively). Nevertheless, the carbohydrate content in the red muscles of this fish remains low (2%). To increase the carbohydrate content which constitute the principal energy source and fiber proportion to improve product digestibility by the animals, cereals (maize flour and rice flour) were used. Four formulae were tested, using the same manufacturing process. A physicochemical study of the finished products was carried out and the Limit Date of Consumption was determined and estimated to 3 years and 3 months.
making the most of these co-products by integrating the concept of sustainable development: the techniques used must be nonaggressive to the environment and must not involve excessive energy expenditure or investment [4]. Today, the fisheries resource development industry is a future component of the fishing industry.
The added value of these products is its contribution to reducing the loss of valuable protein. It may also be the source of new products [5]. Potential field of applications are very broad [6,7]. The most prevalent field is the use for human or pet food. The second is dietary and nutraceutical ingredients. The third is cosmetic and pharmaceutical ingredients and the latter covers various fields of application (agriculture, energy, leather, industry, etc.). The present study concerns the valorization of fishery products and aims at the development of food for young dogs and cats from red muscle co-products, resulting from the processing of tuna. The marine coproduct advancement industry is part of the fish industry branch of the IAA sector. It is also included in the list of primary agricultural processing activities JORT [8]. In fact, valorization is of big interest to both the canned and semi-preserved fish industry, the frozen seafood industry, and the fish-based food industry. The valorization of fish muscle proteins from high quality discarded species has been studied, and these proteins are considered suitable for the preparation of different seafood products with enhanced added value in comparison to the traditional preparation of fish meals or fish oils [9][10][11]. However, we investigate the physicochemical characterization of the red muscles of tuna revealed the richness of these co-products in protein, minerals and fat. The use of these co-products in Tunisia is extremely rare and is limited to the manufacture of fish meal. The incorporation of these red muscles with cereals and sunflower oil in wet foods for young dogs has made it possible to have balanced and stable foods. A physicochemical study of the finished products was carried out and the Limit Date of Consumption was determined and estimated to 3 years and 3 months.

Raw Material
The selected fish species "Atlantique red thon" (Thunnus Thynnus) "yellow thon" (Thunnus albacares) and "pink thon" named also Skip Jack Tuna (Katsuwonus pelamis) were collected from local tuna cannery. Twenty kg of each selected species was separated from commercial ones and distributed in 12kg iced boxes until further processing. Rice flour, corn flour and sunflower oil were purchased from a local provider.

Determination of the Ashes
The percentage of residue is determined by calcinating 1g of dried sample in triplicata for 4 hours at 550°C to constant mass [12].

Minerals Determination
The resulting residues were treated with 5 ml of nitric acid and 5 ml of concentrated chloric acid, the solution is heated until white smoke is released and the acids evaporate. 15 ml of distilled water is added, while continuing the heating for 10 min. The solution was filtered in a 50 ml flask and the volume completed by the distilled water. Mineral contents (K, Mg, Ca, Na, Zn and Fe) were determined by atomic absorption according to the Officials methods of analysis

Determination of Proteins by the Kjeldahl Method:
The percentage of total nitrogen is expressed using the standard

Lipids
Extraction of the fat in the sample was performed using the Soxhlet technique, using petroleum ether as an organic solvent [14].

Assays
Fatty acids were methylated by boron trifluoride in methanol (Sigma) according to the Metchalfe and Schmitz [15] method. The

Rapid Preparation of Fatty Acid Esters for Gas Chromatographic
Analysis [16] and fatty acid methyl esters (FAMEs) were analyzed by gas chromatography (GC) on a Shimadzu (GC-2014) equipped with non-polar DANI-SPA column (50m length, 0.32mm i.d.) and a flame ionization detector. Nitrogen was used as a carrier gas.
The temperatures of the column oven, the injection ports, and the detector were maintained at 165, 250, and 250°C, respectively.
Two microliters of the sample were injected into the column.
Chromatographic peaks were identified by comparing the retention times with those of known standards, maintained at 165, 250, and 250°C, respectively. Two microliters of the sample were injected into the column. Chromatographic peaks were identified by comparing the retention times with those of known standards.

Determination of total Sugar Content
Total sugars were determined using the method described by Dubois et al. [17]. Optical density (DO) was measured at 490nm.

DLC Determination Test
The protocols for performing the DLC analyses or aging tests

Apparent Rate of Deterioration Constant (K):
The relationship between K and temperature T is as shown in The speed apparent constant at temperature T; K0: The constant independent temperature; Ea: Activation energy (cal/g/ mol) or free energy activation: this is the energy that must be supplied to the reagents (heat, UV radiation,.) so that they can react to form products. Reagents must reach a transition state in which the bonds are more fragile, the activation energy corresponds to energy between initial and transient state; R: The perfect gas constant (1,987 cal/g/mol K); T: Absolute temperature (°K).   potassium (170mg/100g MS). The magnesium concentration is in the order of 100 mg/100 g, which is significantly higher (4 times higher) than those described for beef (24mg/100g) [19] or shrimp

Formulation of a New Young Dog's Food Product:
Based

Physicochemical Characterization of Prepared Formulae
The experimental values (Table 5a)

Microbiological Stability Tests and DLC Determination
The microbiological analysis includes total aerobic mesophyll flora, staphylococcus aureus, fecal and total coliforms, ad anaerbic sulfi to reducer flora. Results confirm that the products tested are of good microbiological quality and meet the requirements of the fish canning standard. Despite the relatively high value of water activity (0.941 and 0.916 for the F2 and F4, respectively), the reference germs are absent, this can be explained by the efficiency of the heat treatment at 116°C for one hour after the sterilization procedure [23,24]. And thus, counting the total germs in the food produced results in a consumption limit of three years and three months, without the addition of preservatives or other additives.

Conclusion
Current study is part of the valorization of the red muscles