頁籤選單縮合
題名 | 牛與羊乳冰點調查 |
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作者姓名(中文) | 李素珍; 陳茂墻; | 書刊名 | 畜產研究 |
卷期 | 27:2 1994.06[民83.06] |
頁次 | 頁149-159 |
分類號 | 473.7 |
關鍵詞 | 生牛乳; 生羊乳; 鮮牛乳; 乳冰點; Raw cow's milk; Raw goats' milk; Fresh cow milk; Milk freezing point; |
語文 | 中文(Chinese) |
中文摘要 | 本試驗主要目的在建立本省牛及羊乳冰點之基本資料,並瞭解乳性質、樣品冷藏及加熱對乳冰點的影響。測定牛及羊之乳性質包括乳脂肪、蛋白質、乳糖、無脂固形物、總固形物、酪蛋白、乳清蛋白質、pH、滴定酸度、氯離于濃度、體紐胞數與冰點。並測定冷藏 (3℃,3日)及加熱(63℃ 30 分鐘) 前後之乳冰點,並抽樣分別測定市售鮮牛乳之冰點。 牛、羊個別乳及牛、羊總乳之數目各為 3690、198、774及394,其乳冰點平均分別為一0.5287±0.0465,─0.5543±0.0078,─0.5170±0.0599及0.5452±0.0012℃,變異係數為 8.7、1.4、11.5及0.2%,發現牛乳冰點無論於個別乳或總乳均較羊乳冰點為高,變異係數也較大。如以美國化學分析協會 (AOAC) 之─0.525℃為未攙水之上限,則在此以上之牛個別乳及總乳各佔32 及 48%,而在─0.530℃以上之羊個別乳及總乳各佔 231 及 15.7%。並發現有些羊乳成分與牛乳者有顯著差異,但羊及牛乳冰點間卻無顯著差異,且乳冰點仍維持於狹窄的範圍內。此外,樣品冶藏 (3℃ 放 3 日)及加熱( 60℃加熱 30 分鐘)對牛乳冰點影響不大。市售20家鮮牛乳之冰點,發現樣品間變異很大(-0.561~-0498℃),且超過─0.525℃者佔 52.9%,顯示牛總乳中可能有攙水之嫌。 |
英文摘要 | The main purpose of this experiment was to collect basic data about milk freezing point of dairy cows and goats in Taiwan and to understand the influence of milk property, cold storage and heat treatment on milk freezing point. We exaimed the properties of cows' and goats' milk including the cotent of milk fat, protein, lactose, solids-not-fat, total solids, casein, whey protein, pH, acidity, chloride concentration, somatic cell count and freezing point. The freezing point of cow milk sample before and after cold storage (3 ℃ for 3 days) or heat treatment( 63 ℃ for 30 minutes) and market fluid milk were also randomly tested. Sample number of individual cow, individual goat, bulk cow and bulk goat milk were 3690, 198, 774 and 394 respectively. Average of milk freezing point were -0.5287±0.0465, -0.5543±0.0078, -0.5170±0.0599 and - 0.5452± 0.0012 ℃, and variation coefficient were 8.7, 1.4, 11.5 and 0.2 %, respectively. The results showed that the freezing point either in individuaI or bulk cow milk were higer than goats' milk, as was the variation coefficient. When freezing point -0.525 ℃ (standard of AOAC) was used as the upper limit for unadulterated milk, freezing point above 0.525 ℃ were 32 % from individual cows and 48 % from cow bulk milk, and above -0.530 ℃ were 23.1% from individual goat and 15.7 % from goat bulk milk. We found significant differences between milk composition of cows and goats, but no significant difference between freezing point of cows' and goats' milk. The freezing point still remained within the narrow limits. Besides, we found that there was no significant change due to cold storage (3 ℃ for 3 days) or heat treatment (63 ℃ for 30 minutes). We randomly sampled market fluid milk from 20 dairy plants. Showing the range of milk freezing point was large (-0.561~-0.498 ℃), freezing points above -0.525 ℃ were 52.9 %. It showed that the milk was possibly adulterated with water in cow bulk milk. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。