Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/24857
標題: 屠宰後豬肉品質特性與熱性質之研究
Studies on quality characteristics and thermal properties of pork postmortem
作者: 林烈進
Lin, Lieh-Chin
關鍵字: DSC;示差掃描卡計
出版社: 畜牧學系
摘要: 
中 文 摘 要
原料肉的功能性質是肉品加工成敗的關鍵,為肉品 科技專家研究主要
課題,亦是肉品加工業者最為關心的 項目。
熱示差掃瞄卡計( differential scanning calorimetry,DSC)
可以檢出一複雜蛋白質系統中某一蛋 白質熱變性情形,DSC 技術在肉品
、蛋品、黃豆蛋白等 食品上的研究逐漸普遍,其亦可用以觀察肉類中
蛋白質 的熱性質變化,測定其是否與肉類之鮮度、功能性和非 肉蛋
白物質添加有關。若能利用DSC測定蛋白質熱性 質,可與其他功能
特性加以比較,探討其間之相關性。 故本研究將著重-2℃冷卻24小時
內的豬肉以DSC測定熱 性質與肌肉蛋白質功能性之關係,以求出屠宰
後24小時 內肉類的品質變化,並探討在-2℃及25℃貯存豬肉的
DSC熱性質與HPLC和NMR測定及K-值和揮發性鹽基態 氮及ATP與其關
聯物在貯存時間的變化,以求出與肉類 鮮度及品質的關係。
本研究取屠宰後一小時內豬隻之背最長肌為樣品, 分為試驗Ⅰ及試驗
Ⅱ進行。試驗Ⅰ為冷卻在-2℃條件 下,並分別於0、2、6、12、24小
時時取樣分析,測定豬 肉之中心溫度、pH值、肌節長度、保水力、乳化
力、凝 膠 特性、嫩度、DSC熱性質、鹽溶性蛋白質抽出性、電 氣泳
動模式(SDS-PAGE)及顯微構造的變化等。試驗Ⅱ 為貯存在-2℃及25
℃條件下,並分別於0、12、24、36、 48及96小時時取樣分析,分析項
目包括pH值、總生菌數、 ATP及其關聯物、K值、揮發性鹽基態氮(VBN)
、含磷 化合物之NMR圖譜及電氣泳動模式(SDS-PAGE)。 結
果顯示: 試驗Ⅰ:pH
值略微下降,肌節長度自屠後開始至24 小時變化不大,保水力、乳化
力及鹽溶性蛋白質抽出性 屠宰直後稍高外,隨後至24小時變化不大。
凝膠強度及 嫩度均隨貯存時間增長而降低,樣品組織的顯微構造及
電泳並無顯著變化。DSC熱性質分析,發現六小時前均 有一放熱波峰
,而後肌球蛋白和肌漿蛋白的熱變性溫 度,均隨貯存時間增長而降
低,肌動蛋白則較穩定,而 △H值亦隨貯存時間增加而降低。
試驗Ⅱ:pH值皆下降後再升高,但以-2℃貯存者較 25℃貯存者變化較
少。總生菌數以25℃貯存者較-2℃貯 存者高。 ATP及其關聯物方面,
-2℃貯存者降解較緩 慢,在24小時時,IMP幾達最高值,25℃貯存者
,其變 化較快,24小時後ATP、IMP即快速降解。K值及VBN值 方
面,在-2℃貯存者變化不大,25℃貯存者隨貯存時間 增長而增加。DSC
熱性質分析:-2℃及25℃貯存,均在0 小時時仍可見一放熱波峰,而後
其肌球蛋白及肌漿蛋白 的熱變性溫度隨pH值的下降而下降。肌動蛋白
的熱變性 溫度變化較少。但25℃貯存,96小時時,只剩下兩個熱 變
性溫度。含磷化合物之NMR圖譜中均只剩下sugar phosphate及無機
磷酸。電氣泳動模式方面,-2℃貯存者 變化不大,25℃貯存,48小時前
變化不大,96小時時, myosin heavy chain 及G-actin均有減少的現
象,30 K之 成分,在各時段中均可見。

Studies on quality characteristics and thermal
properties of pork postmortem
Lieh-Chin Lin
Abstract
The functional properties of raw meat influences the
quality of meat products and they are the major topic to
meat scientists and are also what meat processer most
concerned.
Differential scanning calorimetry(DSC) can detect the
thermal properties of protein in the complex food system.
The technique of DSC applied in meat products, egg
procucts and soybean protein...etc, is gradually popular,
and it also can be applied to observe the change and
denaturation of the thermal properties of protein and to
determine the freshness and properties of meat and what
kind of non-meat protein additives exists. So, we can use
DSC to determine the thermal properties of protein, their
interrelation, and to compare with other functional
properties. The purpose of this study was to determine the
relation of the thermal properties of pork chilled at -2℃
for 24hrs based on DSC and the functional properties of
muscle protein and then to find the changes of meat quality
during 24 hrs after slaughtering. We also investigated the
change of pork during storage at -2℃ and 25℃,
respectively. DSC thermal properties, K-value,Volatile
Bacic Nitrogen(VBN) and the change of ATP-related
compounds are determined to find the relationship between
freshness and quality of meat.
In experiment Ⅰ, the M. longissimus dorsi of pork was
chilled at -2℃ and sampled at 0, 2, 6, 12 ,24 hrs to
detect internal temperature, pH value, sarcomere length,
water holding capacity, emulsifying capacity, gelation
characteristics, hardness, DSC thermal porperties, salt
soluble protein estractability, electrophoretic behavior and
scanning electron micrograph(SEM) of pork.In experiment
Ⅱ ,the same samples were stored at -2 and 25
℃,respectively,and sampled at 0, 12, 24, 36, 48, 96 hrs to
detect pH value, total plate counts,ATP-related compounds,
K-value, VBN, NMR-spectra and electrophretic
behavior(SDS-PAGE).The result were as follows:
In experiment Ⅰ :the pH value declined slightly ,
sarcomere length changed few after slaughtering
immediately to 24 hrs , water holding capacity , emulsifying
capacity and salt soluble protein extractibility were slightly
higher after slaughtering immediately but then remained
stable during 24 hrs postmortem . Gel strength and hardness
declined with the storage time increased, significantly.A
exothermic peak and three endothermic peaks including
myosin , sarcoplasmic protein and actin appeared on DSC
thermogram within 6 hrs postmortem,then the transition
temperature(Tmax) of myosin and sarcoplasmic protein
declined with the storage time increased,but Tmax of actin
was more stable, and the △H value also declined with the
storage time increased.
In experiment Ⅱ: the pH value decreased initially then
increased, and pH of the samples stored at -2℃ were more
stable than pH of the samples stored at 25℃.ATP-
related compounds of the samples stored at -2℃ also
remained more stable than that stored at 25℃.And ATP-
related compounds of the samples stored at -2℃ degraded
slower in 24hrs.IMP concentrates almost reached the
highest level; ATP and IMP concentrations of the sample
stored at 25℃ degraded quickly. K-value and VBN value,
the sample stored at -2℃ had few change and those of the
sample stored at 25℃ changed remarkably as the storage
time increased. DSC thermal properties of the samples
stored at both -2℃ and 25℃, could find a exothermic peak
at 0 hr then Tmax of myosin and sarcoplasmic protein
decreased as the pH value declined. The Tmax of actin
changed more less.However, two endothermic peaks existed
in the sample stored at25℃ for 96 hrs. The NMR-spectra of
ATP-related compounds had sugar phosphate and
inorganic phosphate only. Electrophoretogram of the
samples stored at -2℃ did not change remarkably before
48 hrs storage, but myosin heavy chain and G-actin tended
to decrease for the samples stored at 25℃ for 96 hrs. In all
time interval, we can observe the 30K daltons component
appearing on the electrophoretogram.
URI: http://hdl.handle.net/11455/24857
Appears in Collections:動物科學系

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