Study On Effects On Beef Quality Of Qinchuan Cattle Among Different Factor

Qin-chuan beef after-ripening quality were studied via shearing force, pH, TVB-N, cooking loses and color .Explore the relationship between age and tenderness , muscle fibre and tenderness and the tenderization effects of CaCl2 , phosphate, papain and their influence on beef quality and the relationship between muscle fibre gap and tenderness and ultrasonic used in beef tenderness and the effects of Lactobacillus fermentation and quality change on Qin-chuan beef in ferment process .The results as following:1. Beef tenderness of Qin-chuan cattle of 2 years old, 3.5 years old, and 5.0 years old, the tenderness decreased significantly (P<0.05), and muscle fibre diameter thickened significantly with the increment of age (P<0.05).2. Inject different concentration calcium chloride solution (3g/L,5g/L,7g/L, 9g/L, 11g/L) and dip the beef into different concentration of papain solution (0.03g/L,0.05g/L,0.07g/L,0.09g/L, 0.11g/L) and phosphate solution(2g/L,4g/L,6g/L,8g/L, 10g/L). Store the beef at 4℃for 3 days. Measure each sample shearing force and the muscle fibrils gap of the best tenderization effects sample of three factors. The results showed that the tenderization effects of calcium chloride ,papain and phosphate were very significant(P﹤0.01), Comparing with the control and calcium chloride and phosphate the tenderization effects of the papain treatment is very significant(P﹤0.01).The fibre gap of 3g/Lcalcium chloride and 8g/L sodium pyrophosphate were significant(P﹤0.01), but the fibre gap between them were not significant(P﹥0.05). Comparing with the control and calcium chloride and phosphate the fibre gap of 0.09g/L papain treatment is very significant(P﹤0.01), based on the results,the 0.09g/L papain treatment is most increasing the tenderization of beef. The muscle fibrils gap results were the same to the shearing force, It is possible to make the muscle fibrils gap as tenderization index.3. The results show that cooking lose of Qin-chuan beef were significantly decreased by 7.00g/L CaCl2 treatment (P<0.05)and increased when the concentration of CaCl2 higher than 7.00g/L;Three kinds of phosphate significantly decreases cooking lose of Qin-chuan beef(P<0.05); Cooking lose of Qin-chuan beef were significantly decreased by 0.09g/L papain treatment (P<0.05)and increased when the concentration of papain higher than 0.09g/L.4. The lightness(L*value) of beef were increased by 3.00g/L,5.00g/L,7.00g/L CaCl2 treatment and decreased by 9.00g/L, 11.00g/L CaCl2 treatment, CaCl2 treatment has no observed effect on the redness(a*value) of beef(P﹥0.05); Three kinds of phosphate significantly decreases lightness(L*value) of beef (P<0.05) but has no observed effect on the of beef(P﹥0.05); papain treatment has no observed effect on the lightness(L*value) and redness(a*value) of Qin-chuan beef(P﹥0.05).5. Tenderization effects of ultrasound treatment on Qin-chuan beef were studied via Box-Behnken response surface methodology. A model of response was established by design expert software. The results showed the lack of fit was not significant. Therefore, the model could be used to analyze and predict. Based on the results, the tenderization effects of ultrasound intensity and CaCl2 concentration and ultrasound treatment time and interaction between ultrasound intensity and Calcium chloride concentration were very significant on Qin-chuan beef tenderization (P﹤0.01).The effects of interaction of ultrasound intensity and ultrasound treatment time was significant(P﹤0.05). The optimum condition of ultrasound and CaCl2 treatment is ultrasound intensity of 200~220w.m-2 and ultrasound treatment time of 10~15min and 0.25~0.30g/L CaCl2.6. Dip Qin-chuan beef into different concentration of NaCl(10g/L,20g/L,30g/L,40g/L,50g/L) and Lactobacillus(1g/L,2g/L,3g/L) and ferment respectively(1h,2h,3h,4h) ,and Qin-chuan beef quality change in Lactobacillus fermentation were studied via acidity and TVB-N and shearing force. The results show that acid-producing ability of Lactobacillus were decreased with concentration of NaCl increase, acidity of beef were significantly decreased by fermented for 2h under 20g/L~30g/L NaCl condition(P﹤0.05). putrefaction-making bacteria were very significantly inhabited under 20g/L~30g/L NaCl condition (P<0.01). Fermented for 2h by adding 1g/L Lactobacillus or Fermented for 1h by adding 2g/L Lactobacillus very significantly decreases the production of TVB-N(P<0.01). Fermented 1h by adding 2g/L Lactobacillus significantly decreases shearing force of Qin-chuan beef(p﹤0.05).Based on the results: Fermented for 1h by 3g/L Lactobacillus and 30g/L NaCl is feasible.7. Effects of Lactobacillus fermentation on Qin chuan beef were studied via Box-Behnken response surface methodology. A model of response was established by design expert software. The results showed the lack of fit was not significant. Therefore, the model could be used to analyze and predict on Qin chuan beef quality in Lactobacillus fermentation. The effects of Lactobacillus concentration and fermentation time and NaCl concentration were analysed via acidity and amino nitrogen and shearing force. The results showed that optimum conditions of fermentation were 2.53~3.00g/L Lactobacillus and 2.36~3.00h and 22.53~26.98g/LNaCl.On these conditions Qin chuan beef quality index as following: acidity≥1.50g/L,shearing force≤4.00kg.f and TVB-N≤6.28mg/100g.