علوم زیستی دریا
Omid Motamedian; Ahmad Gharekhani; Amir Tukmechi
Abstract
This study aimed at evaluating the use of chitosan as a coat to improve the shelf life of perch fillet. For this purpose, low molecular weight chitosan was prepared and three different levels (0.5, 1, and 2 percentage) were used as a food coat in perch fillet. The samples were stored in refrigerator ...
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This study aimed at evaluating the use of chitosan as a coat to improve the shelf life of perch fillet. For this purpose, low molecular weight chitosan was prepared and three different levels (0.5, 1, and 2 percentage) were used as a food coat in perch fillet. The samples were stored in refrigerator temperature(4 and 7 ºC) for 21 days. Bacterial analysis indicated that coating had significant effects (P<0.05) on reducing the mesophilic and psychrophilic counts with at least a 7-day extension of shelf life. The chitosan-coated products showed lower TBA and pH values than the uncoated samples for up to 21 days of storage at 4°C. The results indicated that the application of chitosan coating significantly improved (P<0.05) the sensory quality of samples. This study thus clearly indicated that the effects of chitosan coating on samples were to retain their good quality characteristics and extend the shelf life during refrigerated storage, which was supported by the results of microbiological, chemical, and sensorial properties.
علوم زیستی دریا
Naser Agh; Abdoljabbar Irani; Farzane Noori; Amir Tookmehchi
Abstract
In this research we investigated the effects of Lactobacillus delbrueckii during three life stages of Acipenser persicus (stage 1: from beginning of exogenous feeding, stage 2: fingerlings with initial body weight of 10 g and stage 3: juveniles with initial body weight of 144 g) on growth performance, ...
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In this research we investigated the effects of Lactobacillus delbrueckii during three life stages of Acipenser persicus (stage 1: from beginning of exogenous feeding, stage 2: fingerlings with initial body weight of 10 g and stage 3: juveniles with initial body weight of 144 g) on growth performance, feeding and survival. In stage one, Artemia nauplii were enriched with probiotics and used as food for Persian sturgeon larvae for 15 days. Shift from live food to dry feed was programmed in seven days followed by rearing until day 30 with dry feed. In stage two (for one month) and stage three (for two months) probiotics were added to dry feed and delivered to fish. At the end of the stage one values of total length, total weight, weight gain and specific growth rate (SGR) of fish fed non-enriched Artemia nauplii (treatment 3) were significantly more than rest of the treatments. Values of total length, total weight, weight gain and SGR of fish fed co-feeding regime (treatment 4) were significantly higher than rest of the treatments at the end of the stage one. Growth performance and survival of experimental fish showed no significant differences amongst the treatments in stage two. Values of total weight, weight gain, SGR and survival of fish fed probiotic supplemented diet were significantly higher than control group in the stage three. It is advised to feed the juvenile fish for at least two months with probiotic supplemented feed in order to improve the growth performance and survival.
Yasaman Khamechin; Ramin Manaffar; Amir Tokmechi; Vida Hojati; Omid Maleki Balajoo
Volume 12, Issue 2 , April 2014, , Pages 56-47
Abstract
Artemia mainly due to its nutrition value and also its merits has been considerate very in research biology and aquaculture. L-carnitine as a food supplement which stimulates the fatty acids oxidation and its affect on increasing of the nitrogen retention and stimulation of resistance against the environmental ...
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Artemia mainly due to its nutrition value and also its merits has been considerate very in research biology and aquaculture. L-carnitine as a food supplement which stimulates the fatty acids oxidation and its affect on increasing of the nitrogen retention and stimulation of resistance against the environmental stresses is used lately in modern aquaculture. In order to study of the effect of dietary L-carnitine supplementationon the growth performance, survival rate and early maturation of parthenogenetic Artemia, treatments were done by 1, 10, 100, 1000mg/l of L-carnitine supplement. The cysts of parthenogenetic Artemia were hatched in optimal conditions. Acquired larvae were fed as long as 15 days with a compound of enriched yeast with HUFA and the alga Dunaliella tertioleca in salinity of 80g/l. L-carnitine supplement was added directly in culture medium and indirectly added by enrichment the algae were fed by specimens. Results revealed that this supplement can stimulate early sexual maturation and aggravates masculinization in all of the experimental groups in comparison with the control group. The best result, in this regard was recorded for 1000 mg concentration of L-carnitine in which at 13th days the best percentage of sexual maturation, 5/04%, was seen. These results showed that L-carnitine has significant effect on growth performance when it exposes in 1000 mg concentration of L-carnitine, also the fatty acids profile in any of these concentration fatty acids DHA is not be.