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1.
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2.
The effect of three smoking durations (60, 90, and 120 min) and two smoking temperatures (60°C and 70°C) on proximate composition and quality of brackish cultured milkfish steaks of 3 cm size was studied. No significant difference was observed in the sensory properties across all the samples, except in the overall acceptability of sample smoked at 60°C for 60 min. There was significant difference in the values obtained for the textures of all the samples. The L*a*b* values showed a significant difference in the raw and smoked samples. The moisture content showed significant difference in all six samples. Naphthalene, fluorine, and anthracene were detected in the raw sample and in all the smoked samples with significant difference, except for naphthalene. The effect of smoking on the sensory properties and the moisture content of a smoked fish sample are dependent on the smoking time and temperature. Polycyclic aromatic hydrocarbon (PAH) concentration in smoked fish can be a factor, based on both water pollution and the smoking procedure. Benzo-a-pyrene and PAH4, which are acceptable indicators of total PAH presence in smoked foods, were not detected in all the smoked samples, thereby indicating the products to be safe for consumption.  相似文献   

3.
Abstract

In this study, the masking or reduction of off-flavor in tilapia due to various preservation methods such as salting, drying, frying, smoking, microwave heating, marinating and fermentation with carbohydrate mixture (som fak preparation) was investigated by subjecting the processed tilapia to sensory evaluation and analyzing the concentrations of geosmin (1,10-trans -dimethyl-trans -9-decaol) in the processed samples. Dry salting or brining muddy-flavored fish and then drying either by hot air at 50°C or sun-drying resulted to only a slight reduction in the geosmin content of the product. Deep-frying reduced the muddy flavor intensity and geosmin content in salted-dried tilapia. Pretreatment of tilapia fillets with acidified brine before smoking reduced geosmin content and masked the muddy flavor in the smoked product. Microwave cooking of fresh muddy-flavored tilapia showed no effect on its geosmin content nor its off-flavor. Marinating tilapia in acetic acid solution resulted in decreased muddy flavor, and longer marinating period led to lower geosmin content in the product. The geosmin content of som fak made from muddy-flavor and non-muddy-flavor tilapia differed significantly, although sensory evaluation yielded no significant differences between the two types of som fak, and the taste panelists preferred the product fermented for 3 days.  相似文献   

4.
ABSTRACT

The diffusion properties of sodium chloride in rainbow trout muscle during dry salting at 10°C were investigated. The average initial dry matter content of the samples increased from 27.80 ± 0.10 to 36.01 ± 0.16%, and the average salt content increased to 17.98 ± 0.38 g NaCl/100 g dry matter at the end of the 10-h dry salting process. The analytical solution of Fick’s second law considering one-dimensional diffusion through an infinite slab was used to calculate effective salt diffusion coefficients (Deff). The Deff values in rainbow trout fillets decreased with increasing salting time and ranged from 6.64 × 10?10 to 16.45 × 10?10 m2/s.  相似文献   

5.
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.  相似文献   

6.
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.  相似文献   

7.
Biochemical and rheological properties of surimi were examined based on: (a) salting time (from 18 to 3 min) while maintaining 21 min for total chopping time; and (b) total chopping time (from 6 to 21 min) while salting during the final 3 min. Extending salting time, which was defined as time of salt contact with proteins during chopping, significantly increased breaking force and penetration distance, while chopping time extension with fixed salting time did not. Salt soluble proteins decreased when salting time decreased; however, this trend performed contrarily against chopping time. A relationship between gel texture and salt soluble proteins was not found. Oxidation of sulfhydryl groups could occur during the chopping process when chopping without salt was extended. Surface hydrophobicity, indicating a certain degree of protein unfolding, was affected differently by chopping versus salting time. Dynamic rheology demonstrated that total chopping time affected denaturation of the myosin tail region more than salting time.  相似文献   

8.
ABSTRACT

The effects of sun drying at ambient temperature in the range of 24°C to 32°C; artificial drying at 35°C, 45°C, or 55°C; or artificial drying at 45°C after treatment with 10% brine, 20% brine, saturated (36%) brine, or dry salt at 28°C for 16 hours on the physical characteristics of the final dried Bombay duck (Harpodon neherius) were studied. Unsalted sundried fish was found unacceptable. Dry salting was more efficient in reducing the moisture level in fish than brining, but was found unsuitable by the panelists due the appearance of a powdered salt crust as the fish dries up. Bombay duck treated with 20% sodium chloride solution, artificially dried at 45°C, and kept in sealed polyethylene pouches was judged superior after sensory evaluation compared to unsalted sundried Bombay duck or unsalted artificial dried Bombay duck at 35°C, 45°C, and 55°C, or artificial dried samples at 45°C after treatment with 10% brine, saturated (36%) brine or dry salt, and kept in sealed polyethylene pouches, respectively, during storage.  相似文献   

9.
ABSTRACT

Smoking is a technique used to improve the sensory attributes and increase the shelf life of fish. The objective of the present study was to evaluate the nutritional, physicochemical, microbiological, and sensory characteristics of sausages made with sea catfish (Sciades herzbergii) fillets subjected to the traditional and liquid smoking processes. The traditionally smoked sausages showed lower (p < .05) moisture content and higher protein, fat, and mineral levels, higher weight loss during processing, higher pH, higher a* (red intensity), and lower L* (luminosity) values. The percentage of shrinkage, water holding capacity, water activity, hardness, cohesiveness, and elasticity were not influenced (p > .05) by the smoking methods tested. The microbial counts of both treatments were in compliance with the current Brazilian legislation. The sensory acceptance of the liquid smoked sausages was higher (p < .05) when compared to the traditionally smoked sausages for the attributes of color, aroma, texture, flavor, and overall acceptance, with scores ranging from 6 (liked slightly) to 7 (liked moderately). Between the two smoking methods tested, liquid smoking presented better sensory acceptance, easier execution, greater process control, and less environmental impact; thus, it is a viable alternative to the traditional smoking of sea catfish (Sciades herzbergii) sausages.  相似文献   

10.
Abstract

The gel forming ability and other characteristics of the mince of 11 underutilized marine fish were studied. They were Bombay duck, silverbelly, sea catfish, silver jewfish, jewelled shad, queenfish, Spanish mackerel, hardtail, Indian tuna, tripletail and false conger eel. Mince was prepared from fillet and a portion of the mince was washed two times with cold water (5°C) containing 0.1% NaCl. Both washed and unwashed mince were ground with 3% NaCl. Ground paste was then stuffed into plastic tube and heated for one- and two-step heating. In the one-step heating, the tubes were subjected to 25°, 30°, 35°, 40°, 50°, 60°, 70° and 80°C for 60, 120 and 180 min. In the two-step heating, the tubes were pre-heated at 25°, 30°, 35°, 40°, 50°, 60°, 70° and 80°C for 60, 120 and 180 min. After the pre-heating, the tubes were immediately subjected to 85°C for 30 min. The gel was subjected to puncture, folding, expressible moisture and sensory tests.

Two-step heating distinctly improved the gel strength compared to the one-step heating. The improvement due to two-step heating was more at low preheating temperatures from 25-35°C. Washing improved the texture and color of all of the gels except Bombay duck and decreased the extent of gel-disintegration in silverbelly, queenfish, sea catfish and hardtail. The gels were set optimally at 35°-40°C for most species. Species variation in the disintegration of the gels was observed. Bombay duck mince produced very weak gel. Neither two-step heating nor washing could improve the gel quality of Bombay duck mince. Our data suggested that jewelled shad, queenfish, silver jewfish, sea catfish, tripletail and false conger eel could be suitable as the material for surimi.  相似文献   

11.
本文研究了腌制鱼的水分活度(Aw值)变化及其与其他有关参数的关系。以鲳鱼作为试验原料,用混合腌渍法对鱼品进行不同时间的腌制,然后观察鱼体中水分活度、盐分含量和水分含量的变化情况,并进一步探索这些参数之间相互的变化关系。实验结果表明,鱼体中水分活度和水分含量的降低,盐分的增加均在开始腌制至18小时时为最快;18小时后变化缓慢;34小时后基本趋向平衡。实验表明,水分活度,盐分含量与水分含量之间存在简单的线性关系,因此在腌制过程中,测定出水分和盐分含量就可以计算出水分活度Aw值,从而达到控制鱼品质量的目的。此方法在提高鱼品的保藏效果上具有一定的实用价值。  相似文献   

12.
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.  相似文献   

13.
The Korean Food Code has approved irradiation less than 7 kGy for microbial control in algal food, which is often not sufficient to achieve the acceptable contamination level (<104 CFU/g). In this study, heat‐assisted low‐dose electron beam (E‐beam) irradiation was applied for improving the microbial quality of dried laver through the response surface optimization of process conditions (Xn); irradiation dose (0–4 kGy, X1), heating temperature (140–180°C, X2) and heating time (0–28 s, X3) for their effects on total aerobic bacteria (TAB) count, moisture content, chlorophyll content, carotenoid content and overall palatability of dried laver. TAB counts were affected more by irradiation dose than by heating temperature and time. Moisture, chlorophyll and carotenoid content and overall palatability were more affected by heating temperature and heating time than by irradiation dose. The overall results indicated that the optimal conditions were irradiation dose of 1.8–3.0 kGy, heating temperature of 154–170°C and heating time of 10–18 s to achieve appropriate quality attributes of heat‐assisted E‐beam irradiated dried laver, such as TAB count of 103 CFU/g, moisture content of 5% and 6.5 of good overall palatability score out of 7.  相似文献   

14.
This study verified the efficacy of common salt (NaCl) in the food and water as a supportive therapy for Ichthyophthirius multifiliis and growth of silver catfish, Rhamdia quelen, fingerlings. After appearance of the first white spots following experimental exposure, indicating infestation by this parasite, fish were transferred to eighteen 40‐L polypropylene tanks and kept for 30 d. Experimental diets were prepared with five different levels of salt supplementation: 0.0, 1.2, 2.5, 5.0, and 6.0% for 30 d. In addition, another group of fish were fed a diet without salt supplementation but exposed to 4 g of salt/L of water. Fingerlings were collected at different times for analyses of whole‐body Na+, K+, and Cl?. Dietary salt supplementation provoked a transitory increase in whole‐body Na+, K+, and Cl? in infested catfish fingerlings, but the best stabilization of these ion levels was observed in specimens exposed to salt in the water. Silver catfish fed a diet containing 1.2% salt showed higher weight and biomass after 30 d compared to those fed with 6% salt. The use of 4 g of salt/L of water improved survival of infested silver catfish, but dietary salt supplementation was ineffective as a therapy for ichthyophthiriasis.  相似文献   

15.
Abstract

An Intermediate Moisture (IM) fish patty was formulated from rockfish mince (85.7%), sorbitol (6.0%), soy protein isolate (2.0%), tapioca starch (2.0%), chicken bouillon (1.3%), refined salt (2.5%), and dried seasonings (0.5%). The mixture was dehydrated at 40 °C for 10 h and vacuum packaged. The dried product had a moisture content of 33% and a water activity of 0.82. The desorption isotherm was sigmoid in shape indicating water activity of the product at ambient temperature in the Philippines would remain stable. Seasonings were added to improve the taste and possibly the stability of the product. Sorbitol addition improved the texture, as judged by a sensory panel, as well as the rehydration index of the patties. Humectat and seasonings improved the overall acceptability of the patties by a sensory panel. Product was prepared with and without preservatives (potassium sor-bate and TBHQ), dehydrated at 40 °C for 10 h, vacuum packed and held at 38°C or ?20°C for two months. Moisture content, water activity, pH, rehydration index, TEA value, Hunter-Gardner color, texture profile, amino acid composition, sensory properties and microbial growth were determined at storage intervals. Instrumental and sensory tests showed no significant differences (p < 0.05) among samples stored with or without preservative and at ?20°C vs. 38°C.  相似文献   

16.
ABSTRACT

Response surface methodology was used to investigate the effect of ultrasound-assisted extraction conditions including solvent:seaweed ratio (10:1–30:1), extraction temperature (30–50°C), and extraction time (30–60 min) on the total phenolic compounds and antioxidant activity of red seaweed (Laurencia obtuse) extracts. The optimum extraction parameters for maximum phenolic content were as follows: solvent:seaweed ratio, 30:1; extraction temperature, 50°C; and extraction time, 42.8 min. The experiment results showed that the solvent:seaweed ratio was the most significant parameter for the extraction. The optimum extraction conditions for maximum antioxidant activity were as follows: solvent:seaweed ratio, 24.3:1; extraction temperature, 45.3°C; and extraction time, 58 min. Under the above-mentioned conditions, the experimental total phenolic content and antioxidant activity value were 26.23 ± 0.75 mg GAE/g seaweed and 120.89 ± 0.81 TEAC, respectively, of seaweed tested, which are well compatible with the predicted contents.  相似文献   

17.
The objective of this study was to determine the physiochemical characteristics and sensory quality of smoked, coarse-ground catfish sausages and catfish frankfurters by using 100% fillets, 75% fillets with 25% nuggets, and 50% fillets with 50% nuggets (the proportions of fillets and nuggets equaled 100% for each of the three formulations). Pork fat was added to each formulation to bring the final fat content to 20%. Lightness (L*) decreased (p < 0.05) as percentage of nuggets increased in frankfurter and coarse-ground sausages. Based on texture profile analysis results, coarse-ground sausages showed lower (p < 0.05) springiness, cohesiveness, hardness, gumminess, and chewiness than frankfurters. Attributes of aroma, flavor, and texture were not affected (p > 0.05) by catfish fillet percentage but were affected (p < 0.05) by sausage type. In addition, no differences existed (p > 0.05) in consumer acceptability among frankfurter samples, with all samples receiving average scores between “like moderately” and “like very much.” Results indicate that catfish fillets and nuggets could be used to produce catfish frankfurters with acceptable sensory properties.  相似文献   

18.
One collagenase (CLS1®) and two proteases (Proleather FG-F® and Protease N®) were used to deskin the peritoneal membrane of catfish nuggets. The factors were used in a full factorial experiment design: enzyme solution concentration (0.2, 0.3, and 0.4% by weight), temperature of enzyme solution (30, 37, and 44°C), and immersion time (10, 15, and 20 min). Contour plots showed that the enzyme Proleather FG-F® maximized whiteness of catfish nuggets at 40–44°C for 15–19 min. Treatment of the enzyme Proleather FG-F® at 0.2% for 15 min had the highest yield (103.4%) at 44°C. Enzymatic skinning has potential in removing the peritoneal membrane from catfish nuggets, improving color (whiteness), and yield.  相似文献   

19.
张保艳  于海洋  程裕东  金银哲 《水产学报》2013,37(12):1854-1862
为了提高复水速率,增强复水效果,采用微波加热的方式,对罗非鱼片进行复水。将提前干燥至水分含量为0.1000 g/g d.b.（干基）的罗非鱼片放入亚克力材料制成的、不同尺寸和形状的容器内,进行微波复水,考察包装容器尺寸、形状及盐含量对微波复水的影响。结果显示,随着复水时间的延长,鱼片的含水率逐渐增高,在250s-300s左右达到最大值并保持稳定。但复水后的样品水分含量没有达到样品的初始水分含量(3.8590 g/g d.b.)。这表明,复水过程是不可逆的,干燥过程中细胞缩水和组织结构破坏导致样品的复水能力下降。实验条件范围内,容器大的容器较利于微波复水（V=115455 mm3）,相较于方形容器,圆形容器更利于罗非鱼片的微波复水。添加NaCl可以增大汤料的介电损失率,使其复水速率增加,复水效果更好。研究表明,微波复水约需240 s就可以达到平衡,比传统的水浴复水（约700 s）可节约约2/3的时间。引用Peleg模型和Weibull模型对实验数据进行拟合,Peleg模型对实验数据的拟合度更高,预测值与实验值呈良好的一致性,更适合描述罗非鱼片的复水过程。  相似文献   

20.
Fillets from Pacific cod (Gadus macrocephalus) were salted with and without polyphosphates (PP) by means of a short three-step salting process. The changes in phosphate and water content during different steps of production were determined by comparing fillets with and without addition of PP. While fillet samples after salt injection and wet-salting contained different water content, from 80.1% to 74.6% depending on processing step and PP addition or not, after dry-salting there was no significant difference in water content between fillets with (58.1%) or without PP (58.9%). Dry-salted fillets with PP addition showed a phosphate content of 6.1 mg P2O5/g. In the following rehydration process (48 h), the total phosphate content dropped down to 2.9 mg P2O5/g, which was lower than the natural total phosphate content of 4.4 mg P2O5/g in the raw material.  相似文献   

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