Study On Meat Quality, Fatty Acids, Volatile Flavor Compounds Of Yak Calf

Beef calve meat of our country depended on import in long-term, higher quality and econo -mic value, and the price of beef is 3 to 6 adult times. In this study, meat samples tested, the age of 6 months of calf yak 6 compared with 2 to 3-years-old adult yak 3, normal development, heal -th, disease-free, combined with stocking (semi-grazing and semi-rearing) had been selected fro -m the main producing areas randomly in Datong County in Qinghai yak. They were butchered togetherand selected longissimus muscle of fresh 2kg from the part of each taking of the thorac -olumbar junction head longissimus muscle. By advanced apparatus and Analysis, example for the amino acids automatic analyzer, the atomic absorption spectrophotometer, atomic fluore -scence spectrometer, high performance liquid chromatography, the gas chromatography-mass spectrum, the solid phase micro extraction and so on. Some traits such as nutritional quality, meat quality, fatty acid composition, volatile flavor material as well as heavy metals and drug residues were tested and analysed. The results were showed that:1. Nutrition indicators: Compared with adult yak, there have significant difference (P<0.05) in meat moisture (76.07%) and protein contents (22.11g/100g) of yak calf meat, and fat (0.85g/100g), ash contents (0.95g/100g) were significantly lower than contrasts (P<0.05); there have significant difference (P<0.05) in VB1 and best significant difference in VB2 (P<0.01); Ca (187.07mg/100g) and Se contents (1.85mg/100g) were higher than contrasts 17.09%, 15.68% (P<0.05), Fe (294.13mg/100g) and Ze contents (242.5mg/100g) were lower than contrasts 75.5 mg/100g, 43.73mg/100g (P<0.05); total amino acids of Calf yak meat (TAA) (76.03g/100g) was lower than contrasts (1.63g/100g), and essential amino acid (EAA) contents (32.85g/100g) was lower than contrasts (1.14 g/100g).2. Meat quality indicators: Meat color (3.17) and marbling scores (3.00) of calf yak were significantly lower than adult yak (P<0.05); the pH24 value was 5.52, the difference of them was not significant (P>0.05); the musclefiber diameter and tenderness shearing force were 23.62μm and 3.46 Kg/cm2, lower than the contrast (P<0.01).3. Fatty acids: The relative content (53.54%) of calf yak meat saturated fatty acids (SFA), accounting for more than half of the total fatty acids was significantly lower than the adult yak (P<0.01); Monounsaturated fatty acids (MUFA) (32.38%) and polyunsaturated fatty acids (PUFA) (11.59%) were significantly higher than adult yak (P<0.01); P:S (0.22) and n-6:n-3 (0.98) were significantly higher than the adult yak (P<0.01), and P:S is 2 times than the adult yak4. Volatile flavor compounds: There were 114 volatile flavor compounds from yak calf. Yak calf meat's total amount less than 9 kinds of those of adult yak, which include less one kind of hydrocarbon, alcohol 6, acid 1, esters 3, heterocyclic 3, and both the same number of aromatic, aldehydes, ketones both. The material of 15 species played a major role on calf yak meat flavor and 11 species of which the relative content of volatile flavor compounds in 1% or more. They were acetaldehyde (fruity, ether hong), propanal,3-(methylthio)- (with onion garlic aroma, meaty), butanal,3-methyl- (the smell of dried cheese), benzaldehyde (fruit, almond flavor), heptaldehyde (fragrance, incense resin, oil and incense), phenylacetaldehyde (honey aroma, aromatic), (e,e)-2,4-decadienal (fat incense, resin incense), 2-pentanone (fruit hong), 2-tridecanone (foul fruit, fat incense), 2-dodecanone (musty and fruity), 3-octenol (meaty, fragrant), citronellol (fruity), benzothiazole (pyridine hong, iron flavor), furan,2-pentyl- (fruit, soil incense), disulfide,dimethyl- (milk aroma).5. Processing indicators: Calf yak meat water holding capacity, cooking loss were 69.43% and 66.84% respectively, significantly higher than adult yak (P<0.05), but the water loss rate was 20.57%, significantly lower than the adult yak (P<0.05).6. Health and safety indicators: Calf yak meat in the detection of Pb and Hg, the value is far below the limit value of"China Compulsory Standard Series"and the largest pollution-free food beef detection, and As was not detected; sulphonamides and furazolidone was also not detected.In short, Calf yak meat has the following advantages: high nutritional value of beef calves, low fat, high protein, amino acid essential amino acid pattern mode and closing to FAO, higher amino acid score, rich in vitamins; muscle fiber texture finer, tender meat, taste better than the adult yak; high content of polyunsaturated fatty acids, muscle fat better quality; flavor; good muscle water holding capacity, excellent processing performance; heavy metals are not exceeded, no veterinary drug residues, heavy metals below standard, no veterinary drug residues, high edible and development value, natural and non-pollution and green foodstuff.