| Summary: | 碩士 === 國立屏東科技大學 === 畜產系 === 91 === Effects of Raw Meat Treatment and Ripening Temperature on the Quality of Chinese Style Dry Sausage
Traditionally Chinese dry sausage manufactured proceeding involving raw meat cooling time; curing treatment and ripening temperature on quality characteristics was investigated. Pork is slaughter at the same day, hind legs and thighs purchased at the traditional market. To determine the effects of cooling time and curing treatment on free water, myofibrillar fragment index (MFI), salt soluble protein (SSP) and free amino acid (FAA) of raw meat and sausage mix; ripening and storage time on microbial, moisture %, water activity (aw), NPN (non protein nitrogen), FAA (free amino acid), acid value and thiobarbituric acid reaction substrate (TBARs) of sausage were also determined.
Curing treatment decreased the increasing of sausage mix on MFI and SSP , after curing 24 h, sausage mix with not curing treatment (control) treatment MFI quickly increased significantly from 74.90 ±3.30 up to 115.80 ±4.00, curing treatment samples up to 83.0 ±4.60 (p＜0.05). Further extended curing to 10 days, MFI increasing was limited and only in control (120.36 ±4.50), but not increasing observed in pre-curing samples. The control samples had an initial SSP concentration 31.58 ±2.21 mg/ml, increased to 36.56 ±0.63 mg/ml at the third day after treatment; the curing samples from 21.7±2.49 mg/ml increased to 31.65 ±2.91 mg/ml, significantly different between treatment and similar curing time. FAA concentration in pre-curing samples increased rapidly than control, after 24 h in curing samples FAA from 42.83±1.91 mg tyrosine /100g increased to 63.95±3.03 mg %, increment was larger than control (40.41±2.12 mg tyrosine/100g). To extended curing to 10 days time, curing samples increased significantly to 65.28 mg tyrosine /100g , control up to 59.75 ±2.42 mg tyrosine/100g . Pre-curing reduced samples moisture, free water and a value (redness) at the first curing day, decreased 5% moisture and 0.6~1.0% in free water, redness then were raising at the second day and maintained in all curing period.
During ripening sausage lost water and water activity significantly, sausage heating at 50℃for 8 h, then were ripened by three temperature at 12,16 and 20℃, had similar tended losing on moisture and water activity, water activity decreased from 0.95 to 0.83 about for 10 days, but sausage ripening at 16℃ had lower water activity than 12 and 20℃at the 10 days curing, ripening at 20℃ mold growth were found on sausage surface at the 7 day. Raw meat utilized for sausage usage cooling for 1 or 3 days before processing, there were not significant affect on quality characteristics of Chinese dry sausage during ripening and storage period. NPN, FAA, acid value and TBARS increased significantly in both cooling time of sausage samples ripening at 16℃for 10 days. The sausage samples from raw meat cooling for 3 days, NPN raised from 3.01±0.199 to 3.84±0.36 mg/100g, the ratio of raising was 27.57%; FAA from 96.74±1.81 significantly increased up to 124.28 mg/100g; and the TBARS increased from 0.8 up to 0.92. Slight decreased microbial numerous of total plate counts, Lactobacillus, Micrococcus and mold at the end ripening day when compared with the day after dry heating. Dry sausage packing with vacuum and stored at 16℃ for 50days, there were not significant changed in moisture, water activity, pH and NPN of dry sausage products, but after 50days stored composition of SSN, FAA and acid value increased significantly with prolong storage time, and the TBARS increasing with each 10 day of storage determined.
Comprehensive from these result, an optimum processing for Chinese dry sausage was postulated that: pork meat cooling 2 days after post-mortem, sausage mix curing 1day, and after dry heating, sausage then ripening at 16℃or 12℃for 10 days.
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