Effect of Vacuum Tumbling with Direct Salting or Brining on Smoked Trout Fillets

Abstract

The following five brining and direct salting treatments were applied with and without vacuum tumbling to rainbow trout, Oncorhynchus mykiss, butterfly fillets: (1) brining, B; (2) direct salting, DS; (3) tumble followed by brining, TB; (4) tumble followed by direct salting, TDS; and (5) tumble with brine, TWB. The water-phase salt content of DS and TDS fillets was the highest while the lowest water-phase salt was found in TWB trout. DS and TDS treatments yielded product closest to the regulatory target of 3.5% water-phase salt. Tumbling followed by brining (TB) produced the softest texture. Tumbling performed before brining did not affect the water-phase salt content of the product.     

Quality Changes in Marinated Anchovy (Engraulis encrasicolus) Sauced with Olive Oil-Lemon Juice Emulsions

ABSTRACT

This study describes the potential use of olive oil-lemon juice emulsions containing different levels of lemon juice (0, 25, 35, and 50% v/v) as a flavoring, preservative, and antioxidant agent in marinated anchovy. The phenolic content and antioxidant activity of lemon juice, olive oil, and olive oil-lemon juice sauces as well as chemical, oxidative, and sensorial changes of marinade samples were analyzed. Increasing the level of lemon juice in sauces retarded the chemical and oxidative changes of marinated anchovy. However, increasing the level of lemon juice more than 35% in sauces led to a decrease in sensorial acceptability. Chemical and oxidative qualities of all the sauced samples were in the limit of deterioration during 100 days of storage. Although marinated anchovy samples treated with sauce containing 50% lemon juice had a significant inhibitor effect on chemical and oxidative deterioration, samples treated with sauce containing 35% lemon juice received the highest overall acceptability score.     

Quality Changes in Gamma Irradiated Marinades of Anchovy (Engraulis anchoita) During Refrigerated Storage

The effect of gamma irradiation (0, 1.8, and 3.3 kGy) on the microbiological, chemical, and color characteristics of marinated (7% acetic acid and 10% NaCl) and vacuum-packed anchovy fillets was analyzed during 20 months of refrigerated storage (4 ± 1°C). Acidity, pH, water activity (a_w), total volatile basic nitrogen (TVBN), lipid oxidation, and color parameters were determined. Mesophilic and psychrotrophic bacteria, sulphite-reducing clostridia, total and fecal coliforms, Staphylococcus spp., yeasts, and molds were investigated. Gamma irradiation reduced the initial mesophilic bacterial counts and inhibited mesophils growth during 20 months. As a result, the production of TVBN during storage was lower in irradiated samples than in control. Also, lipid oxidation was lower in irradiated samples than in nonirradiated. The color of anchovy fillets was not affected by the irradiation treatment. Even if nonirradiated anchovy fillets presented a high stability in comparison with the traditional product (in flasks with vegetable oil and spices), gamma irradiation improved the microbiological and chemical quality of anchovy fillet marinades without inducing changes on its characteristic color for 20 months.     

The Effects of Light Salting on Physicochemical Characteristics of Frozen Cod (Gadus morhua) Fillets

Abstract

The effects of light salting by brine injection and brine immersion on physicochemical and textural properties of cod fillets were evaluated. Light salting significantly increased yield and water holding capacity. Adding brine injection to the process can be used to shorten the process time needed to obtain the desired salt content and increase yield. The effects on chemical composition were most significant in salt content, but water and protein content were also affected. Water content decreased from the tail to head direction of the fillets, both in unsalted and light salted fillets. Changes in protein content were in opposite proportion to changes in water content. This could be seen in the fresh fish and also after freezing, both in unsalted and light salted fillets. Texture of the fish was not significantly affected by salting and freezing.     

Effect of Liquid Smoke Dipping and Packaging Method on the Keeping Quality of Raw and Cooked Chub Mackerel (Scomber japonicus) Fillets

Changes in biochemical and sensory attributes of chub mackerel (Scomber japonicus) fillets during storage treated by immersion in a 12% NaCl brine with or without 0.2% liquid smoke were investigated. Brine-treated chub mackerel fillets were packaged in modified atmosphere or under vacuum and were stored at 4°C. The brined fillets were stored and evaluated raw and after heat treatment as cooked samples. Fish fillets were assessed organoleptically to determine acceptability and by measuring the pH, oxidation levels (TBARS test), and total volatile basic nitrogen (TVBN). Fillets treated in brine with liquid smoke exhibited similar pH and significantly lower TBARS and TVBN values (p < 0.05). The combination of the use of brines containing liquid smoke and subsequent vacuum packaging produced the lowest TBARS and TVBN values and resulted in extended acceptability.     

Characterization of Green Lipped Mussel Meat. Part II: Changes in Physical Characteristics as a Result of Brining and Liquid Smoke Application

The effects of dry or wet brining, different liquid smoke (LS) dipping schedules, and different LS on the weight, water activity, view area, and texture attributes of mussels were compared. Dry brining resulted in significant weight loss (about 30%), whereas liquid brining (4% salt) increased the original weights. With LS dippings, wet brined mussels lost weight, while dry brined samples gained weight. For the same brining and dipping schedule, there was no significant difference between dipping in hickory or in maple LS (p > 0.05). The R² of linear, power, and quadratic polynomial fits to weight versus view area (calculated by image analysis) was 0.8, too low for practical applications. The change in individual mussel weight versus view area was different depending on the brining method. The weight versus view area of wet brined mussels increased and decreased during treatment steps, while dry brined mussels showed a regular decrease in weight versus view area. Texture, measured by texture profile analysis, and water activity also changed significantly upon dry brining (p < 0.05).     

Effects of Injection of Protein Solutions Prepared from Fish By-products on Yield and Chemical Properties of Chilled and Frozen Saithe (Pollachius virens) Fillets

Fish gelatine and protein solutions prepared from saithe by-products were injected into saithe fillets. Effects on weight changes, water holding capacity, and chemical composition of the fillets were investigated after chilled (2, 5, and 7 days) and frozen (14 and 49 days) storage. The results showed that higher weight yields were obtained by adding proteins and salt to the fillets in comparison with only salt, especially in chilled fillets. The drawback of the injection was that higher drip losses were found during storage and thawing than for untreated fillets. Effects of injection on water content were only significant after 2 days of chilled storage, but differences leveled out after longer storage time and with freezing and thawing of the fillets. The procedure applied in this study seems to be promising for utilization of by-products such as trimmings as an ingredient in higher value products like fillets, in comparison to mince products.     

Effects of Potassium Lactate and Acetate on Listeria monocytogenes Inhibition,Physicochemical and Sensory Properties of Smoked Catfish Fillets

The objective of this study was to evaluate the effects of liquid and wood smoking with a potassium lactate (PL) and acetate (PA) combination on the quality and inhibition of L. monocytogenes growth in ready-to-eat (RTE) smoked catfish fillets. Catfish fillets were tumbled with PL and PA, and treated with no smoke (NS), wood smoke (WS), liquid smoke 1 (LS1), and liquid smoke 2 (LS2). Wood smoke with antimicrobials (WSWA) showed greater inhibition (p < 0.05) of L. monocytogenes growth than other treatments with the exception of the LS1 treatment with antimicrobials. Consumers preferred (p < 0.05) smoked catfish fillets treated with WS to LS1 with respect to appearance, odor, flavor, texture, and overall acceptability. In conclusion, the use of PL and PA did not have a negative impact on the quality and sensory properties of smoked catfish fillets but had a synergistic effect with wood smoke constituents that inhibited the growth of L. monocytogenes.     

Proximate Composition and Nutritional Profile of the Black Sea Anchovy (Engraulis encrasicholus) Whole Fish,Fillets, and By-Products

ABSTRACT

In this study, the proximate composition and nutritional profile of the Black Sea anchovy and its by-products were investigated. The total yield of by-products from anchovy was about 32% of the whole fish based on wet weight. The protein and fat contents of anchovy by-products were 13.39 and 10.02% for head, 16.47 and 15.50% for frame, and 12.05 and 23.90% for viscera, respectively. Significant differences were detected among the pH and color properties of anchovy whole fish, fillet, and by-products. Profiles of amino acids, fatty acids, and minerals of anchovy by-products showed they are rich sources of lysine (6–7% of total amino acids), leucine (5–6% of total amino acids), and a number of essential amino acid, polyunsaturated fatty acids (about 32–40% of total fatty acids), n-3 fatty acids (about 27–34% of total fatty acids), eicosapentaenoic acid + docosahexaenoic acid (about 26–32% of total fatty acids), and various minerals (P, Fe, Ni, Ca, Mn, Na, and Zn). These results revealed that anchovy by-products can be utilized for the production of value-added products such as protein powder, protein hydrolyzates, fish oils, and mineral supplements.     

Relationship between Lipid Oxidation,Protein Function Properties,and Freshness Changes of Salt-Treated Blunt-Snout Bream (Megalobrama amblycephala) Fillets Stored at 4°C

The aim of this study was to investigate the relationship between lipid oxidation, protein function properties, and freshness changes of blunt-snout bream (Megalobrama amblycephala) fillets treated with 2% and 4% salt during storage at 4°C. Salting with 2% and 4% salt could delay quality deterioration and protein denaturation, thus improving sensory attributes to some extent. But, 4% salt promoted lipid oxidation of blunt-snout bream fillets. There is a significant correlation (p < 0.05) between freshness indexes and lipid oxidation or protein function properties (total SH content, Ca²⁺-ATPase activity). Salting with 2% salt is an ideal treatment to control the quality of blunt-snout bream fillets stored at 4°C.     

响应面法优化复合咸味剂腌制罗非鱼片的工艺

为开发一种低盐健康新型的使用复合咸味剂腌制罗非鱼片的加工技术,本研究以罗非鱼片为原料,通过单因素实验,考察氯化钠分别与氯化钾、苹果酸钠、白砂糖不同添加量组合对腌制罗非鱼片的感官品质、含盐量、水分含量、蛋白水解指数和质构的影响,采用Box-Behnken响应面法优化复合咸味剂的最佳配比参数。结果显示,氯化钾、苹果酸钠、氯化钠添加量对罗非鱼片品质影响显著,白砂糖添加量对罗非鱼片品质影响不显著;通过Box-Behnken响应面法优化得到复合咸味剂腌制罗非鱼片的最佳工艺条件:氯化钾添加量为2.6%、苹果酸钠添加量为1.3%、氯化钠添加量为9.1%、白砂糖添加量为0.5%。优化后产品的感官评分为89,含盐量为2.81%,表明实验模型可以用于预测实际值。研究表明,与对照组相比,产品的钠含量降低了22.92%,从而为罗非鱼的加工提供了一种低盐低钠快速腌制的加工新技术。     

Biochemical and Sensory Changes of Low-Salt Anchovy (Engraulis japonicus) Sauce Prepared by a Novel Technique

Using a process spanning less than 10 days, a novel technique combining two-stage autolysis and external koji fermentation for the rapid preparation of low-salt anchovy sauce is presented. High-efficiency autolysis of anchovy was achieved by two-stage autolysis, and the second-stage autolysis exhibited a significantly positive effect on the improvement of hydrolysis yield and recovery of anchovy proteins. During the external koji fermentation of hydrolysates from two-stage autolysis, the optimum amounts of added water and salt were determined to be 20% and 8.0%, respectively. By investigating the effect of fermentation time on the biochemical and sensory changes of anchovy sauce, the optimal fermentation time was 8 days. The prepared anchovy sauce had an umami taste, was rich in free glutamate, and contained taurine and γ-aminobutyric acid. In addition, it contained 0.890 g/100 mL amino acid nitrogen (AAN), 1.886 g/100 mL total nitrogen, and 9.76% NaCl. Meanwhile, the recovery of total nitrogen (RTN) was 63.89%.     

Nutrient composition and sensory evaluation of fillets from wild-type Nile tilapia (Oreochromis niloticus, Linnaeus) and a red hybrid (Florida red tilapia × red O. niloticus)

A comparison of composition and sensory evaluation were performed on fillets of Oreochromis niloticus (wild type) and red hybrid tilapia (RHT) (Florida red tilapia ♂× red O. niloticus♀). Fifty male tilapia, 25 O. niloticus (initial weight 159.3 g) and 25 red hybrid (initial weight 132.4 g), were placed in each of three 2.0 m³ volume tanks. The fish were fed a commercial feed containing 35.9% crude protein during the 120‐day experimental period and then killed in cold water (3°C). All the fish were filleted. Twelve fillets from each treatment were used for proximate analyses, five fillets from each treatment were used for fatty acids analyses and the remaining fillets were used for sensory evaluation. The compositional analyses showed similar moisture, true protein and ash content in both genetic groups, but a lower crude fat content was measured in the red hybrid fillets (0.70%) compared with that of O. niloticus fillets (0.97%). No differences between O. niloticus and the red hybrid were observed in their fillet profile of fatty acids. In the sensory evaluation test, a difference in fillet flavour between both genetic groups was perceived. Of the 112 consumers in the preference test, 81.2% perceived a difference in fillet flavour between the two tilapias, with a general preference for the red hybrid over the wild‐type O. niloticus. The benefits of cultivating a RHT with a low lipid content are discussed.     

Effects of Dietary Mineral Supplementation on Quality of Fresh and Salt‐Cured Fillets from Farmed Atlantic Cod,Gadus morhua

The aims of this study were to investigate effects of dietary mineral supplementation on chemical and sensory quality parameters of fresh farmed cod fillets and on the quality of salt‐cured farmed cod. Farmed cod were fed three experimental diets with different levels of mineral supplements (no supplementation, supplementation without zinc and copper, full supplementation) for approximately 2 yr. After slaughter, one‐third of the experimental fish were subjected to chemical and physical analysis, another third were used for sensory analysis and the remaining fish were salt cured. Potassium, copper, and muscle protein were higher in muscle tissue of cod fed full supplementation than cod fed without supplementation. Instrumental color analysis showed that the cut side of fresh fillets of cod fed full supplementation were slightly more green and yellow than fillets of cod fed without extra supplements. A sensory panel could, however, not detect any differences between heated fresh cod given feed with or without mineral supplements. However, the quality of salt ripened cod which had received a complete mineral supplement in the diet was reduced because of increased yellowness, probably caused by the increased level of copper in the muscle.     

Color and Carotenoid Content Changes of Yellow Discolored Channel Catfish,Ictalurus punctatus,Fillets during Refrigerated Storage

Yellow pigment deposition is a quality defect associated with channel catfish fillets. This study evaluated the relationship between fillet color and carotenoid contents as well as the effect of refrigerated storage on the color and carotenoid content of discolored catfish fillets. The color and carotenoid content of the yellow fillets were analyzed using the L, a, b‐color system and high performance liquid chromatography analysis, respectively. A strong linear relationship between visual yellowness (i.e., the b‐values) of fresh catfish fillets and the sum of three major carotenoid contents was observed. Yellow discolored catfish fillets became darker and more yellow during 12 d of refrigerated storage. However, the total carotenoid content of yellow fillets decreased or remained unchanged during storage. Results suggest that while the yellow discoloration of fresh catfish fillets is related to carotenoid contents, the intensification of the discoloration during storage appears to be related to another chemical phenomenon.     

Quality characteristics in raw and smoked fillets of Atlantic salmon, Salmo salar, fed high-energy diets

Atlantic salmon, Salmo salar , were fed four levels of dietary fat (256, 308, 346 and 389 g kg⁻¹ of diet) for 138 days, with the purpose of studying quality characteristics in raw and smoked fish fillets. Dietary fat levels up to 346 g kg⁻¹ resulted in increased fat content of the raw fillets. The dietary fat levels had a less systematic effect on perceived fatness of the smoked fillets and caused a trend towards better odour and flavour. The fat content of raw fillets was significantly ( P ≤ 0.05) correlated to lower smoke odour, greater rancid flavour, fatness, and a yellower hue of the smoked fillets. Astaxanthin levels of the raw fillets varied between 6 and 11 mg kg⁻¹ of fillet and were significantly ( P ≤ 0.05) correlated with greater intensity of smoke odour, lower off-odour, and less whiteness, greater colour intensity and a redder hue of the smoked fish. It is proposed that salmon fillets can be graded according to weight, fat content and colour values prior to smoking to obtain more standardized quality characteristics of the final product after processing.     

The Effects of Natural Antioxidant Extract Isolated from Giant Red Shrimp (Aristaeomorpha foliacea) Shells on Fatty Acid Profiles of Anchovy (Engraulis encrasicolus) During Refrigerated Storage

The aim of the present study was to determine the effects of natural antioxidant extract isolated from the shells of giant red shrimp (Aristaeomorpha foliacea) on the changes in fatty acid profile of anchovy (Engraulis encrasicolus) during refrigerated storage (2.7°C). Total antioxidant activity of shell extract was determined as 45.84%, total phenolic compound as 17.87 mg/100 g shell, and total carotenoid content in shell as 20.31 mg/100 g shell. Total saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), and polyunsaturated fatty acid (PUFA) contents in the control group and the group with 0.1% shell extract addition were found to be affected by the duration of storage (p < 0.05). A percentage increase was determined in MUFA content, while decreases were observed in PUFA content. No statistically significant change was detected in SFA, MUFA, and PUFA contents of groups with added butylated hydroxytoluene (BHT) and 0.5% of shell extract (p > 0.05). It was concluded that the extract isolated from shrimp shells could be used during the cold storage of fish fillets instead of synthetic antioxidants.     

Changes in Protein Oxidation,Water-Holding Capacity,and Texture of Bighead Carp (Aristichthys Nobilis) Fillets Under Chilled and Partial Frozen Storage

This study aimed to evaluate the contribution of protein oxidation to the changes in the water-holding capacity (WHC) and texture of bighead carp (Aristichthys nobilis) fillets under chilled and partial frozen storage (4°C and ?3°C). The results indicated that less protein oxidation occurred to fillets at ?3°C than at 4°C, which was reflected by the higher value of salt-soluble protein contents (SSP), total sulfhydryl content (SH), Ca²⁺-ATPase activity, lower water-soluble protein contents (WSP), total disulfide content (SS), and surface hydrophobicity (So-ANS). However, the fillets had better WHC and texture at 4°C, as well as lower drip loss and higher centrifugal loss, hardness, and springiness. A significant linear relationship existed between protein oxidation parameters with WHC and texture characteristics for fillets under both types of storage, but the process of freezing and then thawing, instead of protein oxidation, was the main factor affecting the texture and WHC of fillets at ?3°C.     

Nutrient Composition of Meat and Uptake of Carotenoids by Artic Char (Savelinus alpinus)

Diets containing 75ppm carotenoids were fed over a 15-week period to Arctic char (Salvelinus alpinus). Carotenoid content in flesh and skin was increased form 1.35 and 10.73 ug/g wet tissue to 5.56 and 41.21 ug/g, respectively. Subsequent feeding over a 7-week period on diets devoid of astaxanthin resulted in a decrease of 66.01 and 55.55% in carotehoid concentrations, Storage of the fillets for up to 12 days at 4°C air or at -20°C under vacuumpackaging conditions for 0 days had little effect on carotenoid retention with only 1.93-8.47% decrease. Crude protein content before feeding carotenoid-containing diets was 19.21% and this increase to 20.25 -21.05% after 15 weeks. The corresponding PER value of before and after feeding was 3.18-3.20 and essential amino acid index of samples varied between 126.45 and 128.77. The caloric values of the unpigmented and pigment4ed fillets were not significantly different. Eicosapentaenoic and docsahexaenoic acids were presented at 6.63-7.43% and 10.78-14.64% in fish fed pigmented diets, respectively and fillets contained between 54.66 and 60.49mg cholesterol/ 100g sample. The major minerals present were potassium and phosphorus, 239.03 and 256.01-274.05 mg% in pigmented fish, respectively. During peimentations, the level of calcium decreased form 18.81 to 6.00-8.80 mg% while the content of B vitamins increased form 3.04 to 5.86 mg%. Free amino acid content in all samples varied between 295.03 and 364.23 mg%. No histamine was detached in any of the products.     

Pre-rigor filleting and drip loss from fillets of farmed Atlantic cod (Gadus morhua L.)

Improved slaughtering procedures of farmed fish may provide sufficient time so that filleting can be performed pre‐rigor while the muscle pH is still high. Such filleting not only reduces fillet gaping but also lowers the transportation costs and makes fresh fillets available to the markets at an earlier stage. The aim of our work was to determine the weight reduction of the fillets due to liquid loss and to study the proteins and enzymes in the drip. After 11 days of cold storage, fillets of farmed Atlantic cod produced pre‐rigor had a weight loss of 10% and a fillet contraction of 19% while for fillets produced post‐rigor the values were 5% and 4% respectively. At the same time, approximately twice the amount of proteins had been lost from the pre‐rigor‐produced fillets. Sodium dodecyl sulphate polyacrylamide gel electrophoresis analysis showed that the proteins in the drip were similar to the sarcoplasmatic proteins extracted from the muscle. Specific analysis of proteolytic enzymes indicated that they are less stable in the expelled liquid than in the flesh during storage. The extensive loss of weight and proteins from pre‐rigor‐produced fillets during subsequent storage must be taken into account if such processing is considered for farmed cod.