Headspace solid phase microextraction chromatography （HS-SPME/GC） was evaluated as a tool in determining the rate of oxidation in oxidized soybean oil samples by measuring the production of hexanal as a secondary ma...Headspace solid phase microextraction chromatography （HS-SPME/GC） was evaluated as a tool in determining the rate of oxidation in oxidized soybean oil samples by measuring the production of hexanal as a secondary major volatile breakdown product of linoleic acid. Samples of the headspace taken from sealed 20 mL vials, incubated 30 min at 50 ~C followed by 5 min adsorption, were injected into a gas chromatograph with 2 min thermal desorption. In applying SPME, different analytical conditions were evaluated. The linearity of response of the volatiles for the HS-SPME/GC procedure using a carboxen-polydimethylsiloxane fiber was determined from 3 g of mineral oil spiked with a hexanal standard solution at different levels. Using the optimized extraction conditions, an R value close to unity （R = 0.999） was found, and the repeatability （n = 1 l） was 6.31%. The results indicated that hexanal is linearly related to peroxide value （PV） only intermediate PV ranges （10-18 meq/kg）. The study also showed that HS-SPME/GC procedure was a simple and reproducible method for the analysis of hexanal in the HS of commercial soybean oil samples, and is useful as a quality control and research tool for the evaluation of flavor quality and shelf life of vegetable oils.展开更多
The objectives of the study were： a） to determine the optimal concentration of the extract that should be incorporated in meat products to maintain the lipid oxidative stability, and b） to verify if the extract exe...The objectives of the study were： a） to determine the optimal concentration of the extract that should be incorporated in meat products to maintain the lipid oxidative stability, and b） to verify if the extract exerted antioxidant activity even when these products were enriched with soybean oil （with fatty acids omega 3）. To carry out these aims, in the first instance the additive was incorporated into meat patties （elaborated with 80% beef and 20% fat plus 2% salt over total mass） at 0, 0.5, 1, 5 and 10 g/kg, respectively. The lipid oxidation was evaluated by measurement of peroxide value during 15 days at 8 ℃ and the results were expressed as reduction percentage of peroxidation （RP）. RP obtained were 55, 49, 73 and 59 respectively. As 5 g/kg was the optimum concentration of antioxidant, this was chosen to add to meat products enriched with soybean oil. In this case the RP obtained was 78%, indicating that the extract decreased lipid oxidation effectively.展开更多
Blended oils have many uses when compared with single oils,due to presence of high Omega9 levels.They help in brain development and reduce the risk of heart diseases.This investigation of blended oils was chosen takin...Blended oils have many uses when compared with single oils,due to presence of high Omega9 levels.They help in brain development and reduce the risk of heart diseases.This investigation of blended oils was chosen taking into consideration the regular use of coconut oil(CO),palm oil(PAO),peanut oil(PO),and groundnut oil(GO),and using these blends three popular South Indian snacks were prepared.The oil blending was in the proportion of 50:50 using four different oils.This study includes the physicochemical properties of blended oils such as their p H,colour,nutritional assessment,and changes in the parameters of mixed oils.Additionally,these oil mixes were utilized for preparing different types of gram flour snacks including potato fries,pakoda,and karasev.The shelf life of the snacks was studied,considering the changes in their synthetic and tangible attributes.The changes seen in the oil separated from the fried items were very close to that of the control.Tangible assessment of the prepared fritters showed that they were synthetically safe to eat for up to two weeks.Six oil blends(CO:PO,CO:PAO,CO:GO,PO:GO,PO:PAO,and GO:PAO)were prepared successfully.Among the blended oils,coconut oil with peanut oil showed the highest spread ability,while groundnut oil with palm oil showed the lowest spread ability.The coconut and groundnut oil blend showed the highest ratio(58.8%)of unsaturated to saturated fatty acids.Polyunsaturated linoleic acid(18:2;24.3%),α-linoleic acid(18:2;5%),oleic acid(18:1;25%),capric acid(2.8%),lauric acid(1.8%),myristic acid(1.6%),palmitic acid(16:0;14.5%),and steric acid(18:0;9.2%)were seen in the coconut and groundnut oil blend.The palm and peanut oil blend showed the least ratio(51.4%)for unsaturated and saturated oils,with oleic acid(21%),lauric acid(1.9%),andα-linoleic acid(2%).Among all the blended oils,coconut oil mixed with groundnut oil showed the highest level of acceptability for gram flour products.The content of free fatty acids was very high in the combination of palm and peanut oil.The three gram flour products prepared using blends of coconut oil and groundnut oil showed good appearance(8%),flavour of the product prepared with combinations of groundnut(refined)oil has high acceptability,good texture(8%),high acceptability(8%)in taste and overall acceptability of sensory evaluation.These blends in the future may develop good quality oils giving a high shelf life to food products.展开更多
Biodiesel is a biomass-based renewable and clean fuel. It can be used directly in existing diesel engines without any modification. In spite of having so many advantages, it has an issue regarding long-term storage st...Biodiesel is a biomass-based renewable and clean fuel. It can be used directly in existing diesel engines without any modification. In spite of having so many advantages, it has an issue regarding long-term storage stability. Biodiesel oxidizes when it comes in proximity of light, temperature, humidity, metals etc. The oxidation causes precipitation and sedimentation in the fuel. Such biodiesel is unfit to use in engines. Hence, this study aims to assess the storage stability of pomelo seed oil （Citrus maxima） biodiesel over a period of five months upon storage both in open and closed condition. Storage stability of biodiesel is determined in terms of acid value, peroxide value and viscosity at regular interval of time. It is observed that there is a strong relationship between oxidation and outside factors such as light, temperature fluctuations and humidity level. Upon exposure to these factors, oxidation in biodiesel accelerated greatly.展开更多
In this paper, the crude camellia oil extracted by cold pressing and deacidified oil, decolorized oil, dewaxed oil and finished tea oil obtained in different refining stages were studied. The changes of acid value, pe...In this paper, the crude camellia oil extracted by cold pressing and deacidified oil, decolorized oil, dewaxed oil and finished tea oil obtained in different refining stages were studied. The changes of acid value, peroxide value and free radical scavenging ability of camellia oil in each stage were compared and analyzed.The results showed that the total phenol content of crude oil was the highest, and the total phenol content of alkali refined crude oil decreased significantly. After dewaxing, the total phenol concentration of camellia oil increased by 63.5%. The reason may be that low temperature conditions contributed to the recovery of phenolic structure in camellia oil, and without the influence of alkaline solution, the damage degree of phenolic substances was greatly reduced, thus elevating the total phenol content. The lowest peroxide value of camellia oil was observed in the alkali-refining deacidification stage, which decreased by 29.3%. Crude oil had the highest acid value and concentration of antioxidant substances. After alkali-refining deacidification,the acid value and the concentration of antioxidant substances dropped by 85.3%and 88.9%, respectively. Total phenols had the strongest correlation with acid value,followed by free radical scavenging ability, and the correlation with peroxide value was not obvious.展开更多
Minced pork paste was mixed with cooked rice and noodle resulted in very popular traditional gourmet meal in Taiwan. The 100 ℃, 4 h was normally cooking condition for commercial business. However, the pressure cooker...Minced pork paste was mixed with cooked rice and noodle resulted in very popular traditional gourmet meal in Taiwan. The 100 ℃, 4 h was normally cooking condition for commercial business. However, the pressure cooker with higher cooking temperature （106 ℃, 116 ℃ and 121 ℃） and different cooking time were under studied in order to improving efficiency, quality and even cost down. The samples of neck pork substitute, cooking at 106℃, 100 rain; 116℃, 75 min; 121 ℃, 45 min with different pressure were perfomed the result as well as traditional 20% fat in ordinary formulation and cooking at 100℃ for 4 h. During storage, the products were taste acceptable for 4 weeks at 4 ℃, 4 months at - 18 ℃ and better than 1 day at 25 ℃ storage.展开更多
In this study, moisture content, peroxide and free fatty acid values and microbial counts of 30 Karinyagi samples taken from different retail markets in Afyonkarahisar province have been investigated. The average mois...In this study, moisture content, peroxide and free fatty acid values and microbial counts of 30 Karinyagi samples taken from different retail markets in Afyonkarahisar province have been investigated. The average moisture content of Karinyagi samples was found to be 17.64%. The average peroxide values of the samples was found 2.33 meq O2/kg fat. Free fatty acid values of samples ranged at 2.2-5.2 mg NaOH/g fat and the average acidity value was found to be 3.43 mg NaOH/g fat. Total aerobic mesophilic bacteria, yeast/mould, coliform group and Micrococcus/Staphylococcus counts of Karinyagi samples were 5.59, 5.54, 2.56, 1.24 log CFU/g fat, respectively.展开更多
文摘Headspace solid phase microextraction chromatography （HS-SPME/GC） was evaluated as a tool in determining the rate of oxidation in oxidized soybean oil samples by measuring the production of hexanal as a secondary major volatile breakdown product of linoleic acid. Samples of the headspace taken from sealed 20 mL vials, incubated 30 min at 50 ~C followed by 5 min adsorption, were injected into a gas chromatograph with 2 min thermal desorption. In applying SPME, different analytical conditions were evaluated. The linearity of response of the volatiles for the HS-SPME/GC procedure using a carboxen-polydimethylsiloxane fiber was determined from 3 g of mineral oil spiked with a hexanal standard solution at different levels. Using the optimized extraction conditions, an R value close to unity （R = 0.999） was found, and the repeatability （n = 1 l） was 6.31%. The results indicated that hexanal is linearly related to peroxide value （PV） only intermediate PV ranges （10-18 meq/kg）. The study also showed that HS-SPME/GC procedure was a simple and reproducible method for the analysis of hexanal in the HS of commercial soybean oil samples, and is useful as a quality control and research tool for the evaluation of flavor quality and shelf life of vegetable oils.
文摘The objectives of the study were： a） to determine the optimal concentration of the extract that should be incorporated in meat products to maintain the lipid oxidative stability, and b） to verify if the extract exerted antioxidant activity even when these products were enriched with soybean oil （with fatty acids omega 3）. To carry out these aims, in the first instance the additive was incorporated into meat patties （elaborated with 80% beef and 20% fat plus 2% salt over total mass） at 0, 0.5, 1, 5 and 10 g/kg, respectively. The lipid oxidation was evaluated by measurement of peroxide value during 15 days at 8 ℃ and the results were expressed as reduction percentage of peroxidation （RP）. RP obtained were 55, 49, 73 and 59 respectively. As 5 g/kg was the optimum concentration of antioxidant, this was chosen to add to meat products enriched with soybean oil. In this case the RP obtained was 78%, indicating that the extract decreased lipid oxidation effectively.
文摘Blended oils have many uses when compared with single oils,due to presence of high Omega9 levels.They help in brain development and reduce the risk of heart diseases.This investigation of blended oils was chosen taking into consideration the regular use of coconut oil(CO),palm oil(PAO),peanut oil(PO),and groundnut oil(GO),and using these blends three popular South Indian snacks were prepared.The oil blending was in the proportion of 50:50 using four different oils.This study includes the physicochemical properties of blended oils such as their p H,colour,nutritional assessment,and changes in the parameters of mixed oils.Additionally,these oil mixes were utilized for preparing different types of gram flour snacks including potato fries,pakoda,and karasev.The shelf life of the snacks was studied,considering the changes in their synthetic and tangible attributes.The changes seen in the oil separated from the fried items were very close to that of the control.Tangible assessment of the prepared fritters showed that they were synthetically safe to eat for up to two weeks.Six oil blends(CO:PO,CO:PAO,CO:GO,PO:GO,PO:PAO,and GO:PAO)were prepared successfully.Among the blended oils,coconut oil with peanut oil showed the highest spread ability,while groundnut oil with palm oil showed the lowest spread ability.The coconut and groundnut oil blend showed the highest ratio(58.8%)of unsaturated to saturated fatty acids.Polyunsaturated linoleic acid(18:2;24.3%),α-linoleic acid(18:2;5%),oleic acid(18:1;25%),capric acid(2.8%),lauric acid(1.8%),myristic acid(1.6%),palmitic acid(16:0;14.5%),and steric acid(18:0;9.2%)were seen in the coconut and groundnut oil blend.The palm and peanut oil blend showed the least ratio(51.4%)for unsaturated and saturated oils,with oleic acid(21%),lauric acid(1.9%),andα-linoleic acid(2%).Among all the blended oils,coconut oil mixed with groundnut oil showed the highest level of acceptability for gram flour products.The content of free fatty acids was very high in the combination of palm and peanut oil.The three gram flour products prepared using blends of coconut oil and groundnut oil showed good appearance(8%),flavour of the product prepared with combinations of groundnut(refined)oil has high acceptability,good texture(8%),high acceptability(8%)in taste and overall acceptability of sensory evaluation.These blends in the future may develop good quality oils giving a high shelf life to food products.
文摘Biodiesel is a biomass-based renewable and clean fuel. It can be used directly in existing diesel engines without any modification. In spite of having so many advantages, it has an issue regarding long-term storage stability. Biodiesel oxidizes when it comes in proximity of light, temperature, humidity, metals etc. The oxidation causes precipitation and sedimentation in the fuel. Such biodiesel is unfit to use in engines. Hence, this study aims to assess the storage stability of pomelo seed oil （Citrus maxima） biodiesel over a period of five months upon storage both in open and closed condition. Storage stability of biodiesel is determined in terms of acid value, peroxide value and viscosity at regular interval of time. It is observed that there is a strong relationship between oxidation and outside factors such as light, temperature fluctuations and humidity level. Upon exposure to these factors, oxidation in biodiesel accelerated greatly.
文摘In this paper, the crude camellia oil extracted by cold pressing and deacidified oil, decolorized oil, dewaxed oil and finished tea oil obtained in different refining stages were studied. The changes of acid value, peroxide value and free radical scavenging ability of camellia oil in each stage were compared and analyzed.The results showed that the total phenol content of crude oil was the highest, and the total phenol content of alkali refined crude oil decreased significantly. After dewaxing, the total phenol concentration of camellia oil increased by 63.5%. The reason may be that low temperature conditions contributed to the recovery of phenolic structure in camellia oil, and without the influence of alkaline solution, the damage degree of phenolic substances was greatly reduced, thus elevating the total phenol content. The lowest peroxide value of camellia oil was observed in the alkali-refining deacidification stage, which decreased by 29.3%. Crude oil had the highest acid value and concentration of antioxidant substances. After alkali-refining deacidification,the acid value and the concentration of antioxidant substances dropped by 85.3%and 88.9%, respectively. Total phenols had the strongest correlation with acid value,followed by free radical scavenging ability, and the correlation with peroxide value was not obvious.
文摘Minced pork paste was mixed with cooked rice and noodle resulted in very popular traditional gourmet meal in Taiwan. The 100 ℃, 4 h was normally cooking condition for commercial business. However, the pressure cooker with higher cooking temperature （106 ℃, 116 ℃ and 121 ℃） and different cooking time were under studied in order to improving efficiency, quality and even cost down. The samples of neck pork substitute, cooking at 106℃, 100 rain; 116℃, 75 min; 121 ℃, 45 min with different pressure were perfomed the result as well as traditional 20% fat in ordinary formulation and cooking at 100℃ for 4 h. During storage, the products were taste acceptable for 4 weeks at 4 ℃, 4 months at - 18 ℃ and better than 1 day at 25 ℃ storage.
文摘In this study, moisture content, peroxide and free fatty acid values and microbial counts of 30 Karinyagi samples taken from different retail markets in Afyonkarahisar province have been investigated. The average moisture content of Karinyagi samples was found to be 17.64%. The average peroxide values of the samples was found 2.33 meq O2/kg fat. Free fatty acid values of samples ranged at 2.2-5.2 mg NaOH/g fat and the average acidity value was found to be 3.43 mg NaOH/g fat. Total aerobic mesophilic bacteria, yeast/mould, coliform group and Micrococcus/Staphylococcus counts of Karinyagi samples were 5.59, 5.54, 2.56, 1.24 log CFU/g fat, respectively.
