The aim of the present study is to investigate the effects of Monascus fermentation on the aroma pattern of semi-dried grass carp. Semi-dried fish was fermented using Monascus purpureus GDMCC3.439. The volatile flavor...The aim of the present study is to investigate the effects of Monascus fermentation on the aroma pattern of semi-dried grass carp. Semi-dried fish was fermented using Monascus purpureus GDMCC3.439. The volatile flavor substances present in fresh fish, semi-dry fish and Monascus fermented semi-dried fish were compared by simultaneous distillation and extraction combined with gas chromatograph-mass spectrometer (GC-MS). The results showed that alcohols, aldehydes and ketones were the main components of the flavor of the unfermented and fermented semi-dried grass crap. Monascus fermentation could significantly affect the volatile flavor substances of semi-dried grass carp. Moreover, the processing of semi-dried fish fermented by Monascus could not only effectively improve the fishy smell of fresh fish, but also make up for the defect of the pickled flavor of semi-dried fish. Eighteen of the main volatile components in semi-dried fish fermented by Monascus were identified by relative odor activity value (ROAV), as follows: 1-octene-3-ol, phenylethanol, hexanal, heptanal, nonanal, (E)-2-octenal, 3-Methyl-1-butanal, benzaldehyde, (E)-2-nonenal, (E,E)-2,4-heptadienal, (E)-2-Decenal, phenylacetaldehyde, (E,E)-2.4-decadienal, tetradecanal, 2,3-butanone, 2,3-octanedione, alpha-pinene, 2-pentane furan.展开更多
Current research emphasis has been on the reduction of feed cost by incorporating processed sesame seed meal in the diet of tilapia. Raw sesame(Sesamum indicum) seed was soaked and subjected to either autoclaving or f...Current research emphasis has been on the reduction of feed cost by incorporating processed sesame seed meal in the diet of tilapia. Raw sesame(Sesamum indicum) seed was soaked and subjected to either autoclaving or fermentation, after which their oil contents were mechanically extracted. Graded levels of autoclaved(71.2,165,5 and 296.3 g/kg designated as diets 1, 2 and 3, respectively) and fermented(71.0,164.3 and 292,2 g/kg designated as diets 4, 5 and 6, respectively) sesame seed meal were included into fishmeal based diets for Til-aqua natural male tilapia(NMT) fry(initial weight,1.69 ± 0.02 g), A diet without sesame seed meal served as the control. Diets were approximately iso-nitrogenous(35% crude protein). Fish were fed 5 times their maintenance requirement, which was 3.2 x 5 x [fish weight(g)/1,000]^(0.8) daily for 56 days. Processing improved the nutritional profile of raw sesame seed meal in terms of its crude protein and antinutrient compositions. Growth performance of fish was similar(P> 0.05) in the control and dietary treatments. The group fed diet 3 exhibited significantly poorer feed conversion ratio(1.14), protein efficiency ratio(2.77) and economic conversion ratio(US$1.38/kg) relative to the group that received diet 5. Apparent digestibility coefficients for protein, lipid and energy in diet 3 were similar(P > 0.05) to those in diet 6 but significantly lower(P < 0.05) than those of the control and other dietary groups. The sesame seed meals processed with different methods did not significantly affect crude protein, crude lipid and gross energy compositions in the fish carcass. The study demonstrated that71.2 g/kg of autoclaved and 164.3 g/kg of fermented sesame seed meal could be incorporated in the diet of Til-aqua NMT with cost benefit.展开更多
Liquid fermented fish(Nam pla ra)is a traditional local condiment and popular consumption in Thailand.According to previous research,tilapia frame could be used as a raw material for the production,but the amount of p...Liquid fermented fish(Nam pla ra)is a traditional local condiment and popular consumption in Thailand.According to previous research,tilapia frame could be used as a raw material for the production,but the amount of protein received is still below the standard.In addition,there is no information of additives in curing process on consumer preferences.In this research,response surface methodology was used to study the influence of extracted protein from soybean meal(5-15%)and salt(15-20%)contents on chemical characteristics of Nam pla ra after 4 months of fermentation.The amount of roasted rice and roasted rice bran addition in curing process on sensory preferences were also studied.The results showed the linear effect of extracted protein and salt contents on NaCl content(P<0.05).When extracted protein increased,NaCl content of sample decreased,while increased salt concentration,NaCl content increased.Extracted protein showed linear relationship with autolytic degradation products and formaldehyde nitrogen of sample(P<0.05).Increase in extracted protein concentration caused an increment to both autolytic degradation products and formaldehyde nitrogen.In addition,salt content showed linear relationship with protein,total nitrogen,ammonia nitrogen and amino nitrogen(P<0.05).When increased salt concentration,protein and all kind of nitrogen tested in this study decreased.The statistical models for protein and NaCl contents(as an index of product quality)and our experimental validation,indicated that the models were appropriate to predict values.For acceptability test,there was no significant different in all attributes scores of cured samples with 10%roasted rice,roasted rice bran and mixture of both.In addition,their showed a significant different in all attributes scores lower than the commercial sample.In conclusion,the highest protein content was found in a treatment prepared by added salt content 15%by weight of digested material.Addition of proteins extracted from soybean meal did not lead to increase in protein content of finished product.However,chemical properties of all treatments could meet Thai community product standard.展开更多
文摘The aim of the present study is to investigate the effects of Monascus fermentation on the aroma pattern of semi-dried grass carp. Semi-dried fish was fermented using Monascus purpureus GDMCC3.439. The volatile flavor substances present in fresh fish, semi-dry fish and Monascus fermented semi-dried fish were compared by simultaneous distillation and extraction combined with gas chromatograph-mass spectrometer (GC-MS). The results showed that alcohols, aldehydes and ketones were the main components of the flavor of the unfermented and fermented semi-dried grass crap. Monascus fermentation could significantly affect the volatile flavor substances of semi-dried grass carp. Moreover, the processing of semi-dried fish fermented by Monascus could not only effectively improve the fishy smell of fresh fish, but also make up for the defect of the pickled flavor of semi-dried fish. Eighteen of the main volatile components in semi-dried fish fermented by Monascus were identified by relative odor activity value (ROAV), as follows: 1-octene-3-ol, phenylethanol, hexanal, heptanal, nonanal, (E)-2-octenal, 3-Methyl-1-butanal, benzaldehyde, (E)-2-nonenal, (E,E)-2,4-heptadienal, (E)-2-Decenal, phenylacetaldehyde, (E,E)-2.4-decadienal, tetradecanal, 2,3-butanone, 2,3-octanedione, alpha-pinene, 2-pentane furan.
文摘Current research emphasis has been on the reduction of feed cost by incorporating processed sesame seed meal in the diet of tilapia. Raw sesame(Sesamum indicum) seed was soaked and subjected to either autoclaving or fermentation, after which their oil contents were mechanically extracted. Graded levels of autoclaved(71.2,165,5 and 296.3 g/kg designated as diets 1, 2 and 3, respectively) and fermented(71.0,164.3 and 292,2 g/kg designated as diets 4, 5 and 6, respectively) sesame seed meal were included into fishmeal based diets for Til-aqua natural male tilapia(NMT) fry(initial weight,1.69 ± 0.02 g), A diet without sesame seed meal served as the control. Diets were approximately iso-nitrogenous(35% crude protein). Fish were fed 5 times their maintenance requirement, which was 3.2 x 5 x [fish weight(g)/1,000]^(0.8) daily for 56 days. Processing improved the nutritional profile of raw sesame seed meal in terms of its crude protein and antinutrient compositions. Growth performance of fish was similar(P> 0.05) in the control and dietary treatments. The group fed diet 3 exhibited significantly poorer feed conversion ratio(1.14), protein efficiency ratio(2.77) and economic conversion ratio(US$1.38/kg) relative to the group that received diet 5. Apparent digestibility coefficients for protein, lipid and energy in diet 3 were similar(P > 0.05) to those in diet 6 but significantly lower(P < 0.05) than those of the control and other dietary groups. The sesame seed meals processed with different methods did not significantly affect crude protein, crude lipid and gross energy compositions in the fish carcass. The study demonstrated that71.2 g/kg of autoclaved and 164.3 g/kg of fermented sesame seed meal could be incorporated in the diet of Til-aqua NMT with cost benefit.
文摘Liquid fermented fish(Nam pla ra)is a traditional local condiment and popular consumption in Thailand.According to previous research,tilapia frame could be used as a raw material for the production,but the amount of protein received is still below the standard.In addition,there is no information of additives in curing process on consumer preferences.In this research,response surface methodology was used to study the influence of extracted protein from soybean meal(5-15%)and salt(15-20%)contents on chemical characteristics of Nam pla ra after 4 months of fermentation.The amount of roasted rice and roasted rice bran addition in curing process on sensory preferences were also studied.The results showed the linear effect of extracted protein and salt contents on NaCl content(P<0.05).When extracted protein increased,NaCl content of sample decreased,while increased salt concentration,NaCl content increased.Extracted protein showed linear relationship with autolytic degradation products and formaldehyde nitrogen of sample(P<0.05).Increase in extracted protein concentration caused an increment to both autolytic degradation products and formaldehyde nitrogen.In addition,salt content showed linear relationship with protein,total nitrogen,ammonia nitrogen and amino nitrogen(P<0.05).When increased salt concentration,protein and all kind of nitrogen tested in this study decreased.The statistical models for protein and NaCl contents(as an index of product quality)and our experimental validation,indicated that the models were appropriate to predict values.For acceptability test,there was no significant different in all attributes scores of cured samples with 10%roasted rice,roasted rice bran and mixture of both.In addition,their showed a significant different in all attributes scores lower than the commercial sample.In conclusion,the highest protein content was found in a treatment prepared by added salt content 15%by weight of digested material.Addition of proteins extracted from soybean meal did not lead to increase in protein content of finished product.However,chemical properties of all treatments could meet Thai community product standard.
