The Quality Changes Of Camellia Oil Used For Frying

Camellia oleifera Abel is mainly distributed in the south of China. Camellia oil is used as a favorite cooking oil extracted from the seed of Camellia oleifera. In the main producing areas, such as Hunan, camellia oil has been used to fry by locals people for a long history. Because of its taste, color and odour, snacks fried with camellia oil are local people's favorite subjects. But the data about the quality changes of camellia oil during frying are rare, so it is important to understand what happens during frying of camellia oil.Camellia oil abtained from hunan province compared with the the palm oil purchased from local market were used as materials for frying. The conventional indices of the camellia oil and palm oil at the different stages of frying according to those described in Chinese standards. And then the volatile components of camellia oil and palm oil were assessed by Head Space Solid Phase Micro-extraction (HS-SPME) coupleed with GC. Meanwhile the french fryers fried with above two kinds oil were evaluated by sensory evaluationand fuzzy method. The main results were shown as follows:Within 30 h of frying, acid value, peroxide value of camellia oil were less than those of palm oil; the saponification value of camellia oil droped from (214.9127±0.6181) mg/g to (210.8781±0.4342) mg/g, but the saponification value of palm oil showed no irregular chage; the iodine value of camellia oil decreased from (88.9394±0.1886) g I2/100g to (69.5445±0.1561) g I2/100g, while the iodine value of plam oil decreased from (48.739±0.2,28) g I2/100g to (20.519±0.107) g I2/100g. K232 and K270 values of palm oil were less than those of camellia oil of after 18 h of frying. The carbonyl values of camellia oil and palm oil were over the limit required in the standard at 24 h of frying. Considering the requests in the standard, the frying life of camellia oil should be 24 hours.The volatile components of camellia oil and palm oil was conducted by Head Space Solid Phase Micro-extraction (HS-SPME) coupled with GC during frying. With respect to total peak area, palm oil was more than camellia oil at the beginning of frying, but after 30 h, total peak area of palm oil was less than camellia oil; Whenever beginning or ending frying,the contents of decanol, octyl aldehyde, benzaldehyde, hexanal of palm oil were much more than those of camellia oil. The ethyl acetate content of palm was almost like that of camellia oil.French fryers fried by two kinds oil were researched by sensory evaluation and fuzzy method. The product of camellia oil was more susceptible by the panelists than the product of palm oil.1st and 72th batchs of fryers fried by camellia oil were most likely received; while 24th and 48th batchs were more likely received; but 96th batch was more difficultly received.1st batch of fryers fried by palm oil was most likely received; while 24th batch was more likely received and; and 48th and 72th batchs 96th batch were general recevied; but 96th batch was more difficultly received. Acid value, carbonyl value, volatile components and K values in the camellia and palm oils in fryers at 72th and 96th batchs were less than those in the relative frying oils. The values described above in fryers fried by camellia oil were less those of palm oil.