Evaluation of Physicochemical and Sensory Properties of Sausages Made with Washed and Unwashed Mince from Nile Tilapia By-products

This study evaluates the effects of inclusion level (60 to 100%) and washing cycles (0 to 2) of minced fish from Nile tilapia fillet by-products on proximate composition, mineral contents, color, hardness, and sensory acceptance of sausages. A complete 2² factorial experimental design was used. Regression models for protein, fat, moisture, minerals, color, and hardness were developed. The optimum combinations for the independent variables are sausages made with 100% non-washed minced fish, which represents a better use of by-products without generating washing residues, leading to less expensive sausage with higher nutritional value.     

Replacement of Rice Flour by Meat Flour Mechanically Separated from Tilapia on the Technological,Nutritional, and Sensory Quality of Salted Gluten-free Cookies

ABSTRACT

This work evaluated the technological, bacteriological, and sensorial quality of cookies produced with increasing levels (0%, 10%, 20%, 30%, and 40%) of mechanically separated meat flour from tilapia (MSMF) to replace rice flour (RF) in order to identify the optimal level without compromising the overall quality of the product. The cookies were analyzed for expansion index (EI), specific volume (SV), hardness, color, water activity (a_w ), coagulase-positive staphylococci, coliforms at 45°C, Salmonella spp., and sensory acceptance. The inclusion of MSMF affected (P < .05) some characteristics such as EI, SV, a_w , hardness, and color (L*, a*, b*), but all formulations met the legal bacteriological standards. Cookies with 20% substitution of RF by MSMF presented 58.82% carbohydrates, 18.53% proteins, and 11.31% lipids, and was the most accepted (P < .05); 51% of consumers rated it with a score of six or higher (above I liked slightly). It is concluded that the substitution of 20% of RF by MSMF can be used for nutritional enrichment of widely consumed conventional products.     

Effects of Bicarbonate,Xanthan Gum,and Preparation Methods on Biochemical,Physicochemical, and Gel Properties of Nile Tilapia (Oreochomis niloticus Linn) Mince

This study was aimed to determine the effects of phosphate compound substitutions (sodium bicarbonate and xanthan gum) and preparation methods—headed, gutted whole fish, and mince; fresh and after frozen storage (?20°C for 3 months)—on Nile tilapia mince qualities. Results showed that bicarbonate (0.3% with 8% sucrose/sorbitol) is an efficient phosphate compound replacement as evidenced by the comparative values of salt extractable protein, Ca²⁺-ATPase activity, total sulfhydryl content, and textural properties to those of the phosphate-added—0.3% sodium tripolyphosphate (STPP) with 8% sucrose-sorbitol—sample after 3-month frozen storage (p > 0.05). Both cryoprotected samples containing STPP or bicarbonate exhibited higher denaturation temperatures of myosin than others. Xanthan gum (0.5%) could neither stabilize the biochemical and physicochemical properties of mince during 3-month frozen storage nor improve textural properties of gel from frozen whole fish.     

Development of Quality Index Method Scheme for Common Carp (Cyprinus carpio) Stored in Ice: Shelf-Life Assessment by Physicochemical,Microbiological, and Sensory Quality Indices

ABSTRACT

Sensory methods are the most interesting methods to estimate fish quality. Among these, the recently developed quality index method (QIM) has gained popularity, as shown by the multiple publications of QIM schemes in the last years. The objective of this study was to create a new QIM scheme (QIM sensory table and corresponding point system) for the common carp (Cyprinus carpio), basing the definition of the rejection point on sensory, physicochemical (thiobarbituric acid reactive substances, total volatile basic nitrogen, pH, and color measurements), and microbiological criteria (counts of mesophiles, psychrotrophs, and Pseudomonas spp.). A new QIM scheme was developed and is proposed for use in the future; it will be useful for practical evaluations of carp freshness in all steps of the production chain, and it will contribute to a more effective use of the species as an alternative for human food supply.     

Preparation,Gel Electrophoresis Analysis,and Nutritional Evaluation of a Functional Krill Protein Concentrate with Low Fluoride Level from Antarctic krill (Euphausia superba)

A functional krill protein concentrate (FKPC) with low level of fluoride was prepared from frozen Antarctic krill (Euphausia superba) using isoelectric precipitation and phosphoric acid treatment. Variations in proteins and nutritional properties of the FKPC were analyzed. Gel electrophoresis analysis indicated that some variations in protein composition were introduced by autolysis and pH shift during the process of isoelectric precipitation and fluoride removal. The FKPC was composed of 81.01% ± 0.45% crude protein (dry basis) and 16.78% ± 0.26% total lipid (dry basis), exhibited excellent amino-acid composition in all the essential amino acids, exceeding the requirements of the FAO/WHO/UNU for food protein, and was rich in omega-3 polyunsaturated fatty acids, especially eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids present in phospholipids. The fluoride level of FKPC was 79.79 ± 2.10 μg/g (dry basis), which met the USFDA requirements. The surimi yield reached 43.74%, and the mean recovery rate of protein and fat was 52.68% and 41.44%, respectively. The nutritional value, safe level of fluoride, and high yield rate provide evidence that FKPC has a promising future in the food industry as a new aquatic protein and lipid resource.     

A comprehensive evaluation of replacing fishmeal with housefly (Musca domestica) maggot meal in the diet of Nile tilapia (Oreochromis niloticus): growth performance,flesh quality,innate immunity and water environment

A 10‐week feeding trial of using housefly (Musca domestica) maggot meal (MM) in practical feeds for Nile tilapia (Oreochromis niloticus) was conducted to assess the growth performance, ingredient utilization, flesh quality, innate immunity and its influence on water environment. Fish were fed five isonitrogenous and isoenergetic diets, where fishmeal (FM) was substituted by MM at the level of 0, 90, 180, 270 and 360 g kg^‐1 diet (remaining FM content: 360, 270, 180, 90 and 0 g kg^‐1). There was no significant difference in feed intake and apparent digestibility coefficient between the treatments. Replacing up to 270 g kg^‐1 FM did not have an impact on the growth performance and ingredient utilization, whereas the complete replacement of FM caused significantly lower survival rate, weight gain, specific growth rate and higher feed conversion rate. Dietary MM was also proved positively influential in flesh quality, whereas replacing 180 g kg^‐1 or more FM suppressed the innate immunity of tilapia. When compared by the effects on the water environment, the increasing substitute levels were accompanied with the declining concentrations of nitrite nitrogen and total phosphorus in the water. Our study verified the feasibility of using MM as a partial substitute of FM in aquatic feed. When replacing 180 g kg^‐1 FM (corresponding to half of the FM content in control diet) in the diet of Nile tilapia, it can serve as a renewable and environmentally superior alternative without compromising the performance criteria.     

Transference of heavy metals (Hg,Cu, Pb and Zn) with the trophic structure in a polyculture pond: evidence from nitrogen stable isotope

Concentrations of heavy metals, including Hg, Cu, Pb and Zn, in sediment and different organisms as well as the transference through the food web in a polyculture pond were investigated. The δ¹⁵N values of consumers showed a gradual enrichment with increasing trophic positions from the filter‐feeding bivalves (δ¹⁵N = 10.93 on average) to the predators (δ¹⁵N ≥ 12.59 for all crustacean and fish). Concentrations of heavy metals in sediments followed the decreasing order: Cu ≈ Zn > Pb > Hg, while in organisms, the order was Zn > Cu > Pb > Hg. Concentration of Cu was negatively related to the δ¹⁵N values of the animal tissues (P < 0.05), indicating the decrease in the Cu concentration with increasing trophic positions. Concentrations of Hg, Pb or Zn did not show significant relationship to the trophic positions. Food sources and feeding guilds of organisms might be more important factors determining the heavy metal concentrations in the body tissues of aquatic animals than their trophic positions.     

中国海才女虫属复合体(多毛纲:海稚虫科)种类记述

才女虫属复合体隶属于多毛纲、海稚虫科,是多毛纲中寄生种类多样性最高的群体之一。本文描述了该复合体在中国海所分布10种的形态学特征和生物学属性。此10种分别为吻蛇稚虫、小蛇稚虫、美角才女虫、难定才女虫、腺袋才女虫、邻近才女虫、触角伪才女虫、膜质伪才女虫、短鳃伪才女虫和网格伪才女虫。其中,邻近才女虫为一新种,该新种主要形态学特征在于其尾部背、腹面皆具缺刻,且头部背面无中触手。中国海分布的大多数才女虫属复合体种类既可以在松软底质上营管栖生活,也可以寄生于某些海洋生物。本文报道的种类中只有邻近才女虫和短鳃伪才女虫未见有寄生现象。中国海才女虫属种类最常见的寄主是贝类(双壳类、腹足类)和珊瑚。     

Case report: concurrent herpesviral and presumptive iridoviral infection associated with disease in cultured shortnose sturgeon,Acipenser brevirostrum (L.), from the Atlantic coast of Canada

Approximately 8 weeks after a chlorine insult associated with the city water supply, shortnose sturgeon, Acipenser brevirostrum (L.), from one group presented with small (3–4 mm) irregular foci of cutaneous pallor that involved the dorsocranial integument with progressive ulceration of the nascent lesions. Various bacterial organisms were isolated from the cutaneous lesions, but not from the internal viscera. Histologically, the nuclei of the intralesional and perilesional epidermal cells often exhibited margination of the chromatin that resulted in a homogenous, pale, amphophilic, tinctorial quality of the nucleoplasm consistent with a herpesvirus infection. In addition, rare lamellar epithelial cells were prominently enlarged due to an abundant, dense, basophilic cytoplasm characteristic of an iridovirus infection. Inoculation of cutaneous lesion and kidney, spleen, liver sample pools from affected shortnose sturgeon onto white sturgeon spleen (WSS‐2) cell line induced cytopathic effect characterized by syncytia formation. Ultrastructural analysis of infected WSS‐2 cells revealed viral particles with a characteristic herpesvirus morphology. Intranuclear hexagonal capsids had a diameter of 95–108 nm, and enveloped particles present in the cytoplasm of infected cells had a diameter of 176–196 nm. This is the first report of a herpesvirus and a possible iridovirus‐like infection in shortnose sturgeon.