Research On Antioxidant Activities And Flavor Of Jinhua Ham During Its Fermentation Prophase

Jinhua ham was famous for its delicious color, unique fragrant and clean appearance design, forming its unique features in color, aroma, taste and appearance. So, Jinhua ham was known around China in cured meat period and had an important influence in theories and techniques in meat products processing. But in a long time, production process we used was relatively out of date, comparing European production process. This situation resulted in many hidden dangers in health, security, nutrition etc, furthermore hard to satisfy some modern consumption concepts and food safety regulations which limited Jinhua ham development and growth. This article provided some basic theories for production processing of Jinhua ham by studying basic chemical elements, antioxidant activity, fat peroxide and ham flavor of four different parts, which were fire heel, upper part, middle part and oil drip, from Jinhua ham during its fermentation period. Main conclusions were as follows:Firstly, water content of all the four parts showed significantly decrease during fermentation prophase. Sodium chloride content of the upper part, middle part and oil drip presented upward trend, but changes of sodium chloride of fire heel weren’t obvious. Ash content of upper part, middle part and oil drip showed slight upward trend, but fire heel showed downward trend. Protein content increased at first and decreased later.Secondly, total antioxidant values ascended at first and fall later overall for all the four parts. When ABTS method was applied, antioxidant activity of fire heel, upper part and oil drip reached a maximum at the fourth week, which were 58.2 mmol Trolox Eq./kg sample,49.8 mmol Trolox Eq./kg sample and 58.1 mmol Trolox Eq./kg sample respectively. As a contrast, antioxidant activity of middle part reached maximum at the third week which was 55.9 mmol Trolox Eq./kg sample. If DPPH method was used, antioxidant activity of upper part and middle part achieve maximum which were 24.8 mmol Trolox Eq./kg sample and 25.5 mmol Trolox Eq./kg sample respectively at the third week. Antioxidant value of fire heel and oil drip attain maximum which were 26.3 mmol Trolox Eq./kg sample and 26.5 mmol Trolox Eq./kg sample respectively at the fourth week. By using the FRAP method, antioxidant values of fire heel, upper part, middle part and oil drip achieved maximum which were 4.3 mmol Trolox Eq./kg sample,4.3 mmol Trolox Eq./kg sample,4.5 mmol Trolox Eq./kg sample and 4.8 mmol Trolox Eq./kg sample respectively at the fourth week.Thirdly, relative content of saturated fatty acid of fire heel ascended at first and decreased later during Jinhua ham’s fermentation period. Relative content of monounsaturated fatty acid of fire heel showed decrease trend first and increase trend then. As a contrast, relative content of polyunsaturated fatty acid of fire heel decreased slowly. Relative content of saturated fatty acid and monounsaturated increased first and fell down later for the upper part, but its polyunsaturated fatty acid decreased first and increased later. For the middle part, its saturated fatty acid relative content increased slowly and its monounsaturated fatty acid decreased firstly and increased then. Relative content of polyunsaturated fatty acid of middle part ascended at first and fell down later.Last for the oil drip part, its saturated fatty acid relative content declined at first and went up later, and monounsaturated fatty acid relative content rise firstly and dropped later. Relative content of polyunsaturated fatty acid show decline significantly. Last but not the least, flavor compounds of Jinhua ham can be concluded as aldehydes, acids, hydrocarbons, alcohols, ketones, esters and so on during its fermentation prophase. Among them, relative content of aldehydes and ketones were the most and relative content of caproaldehyde was the most abundant at the single flavor substances point. Although relative content and types of flavor substances still existed, a certain gap between this Jinhua ham and maturated ham, main ingredients can be detected and took the dominant place.