BITTER TASTE OF ENZYMATIC HYDROLYSATES OF CASEIN .1. ISOLATION, STRUCTURAL AND SENSORY ANALYSIS OF PEPTIDES FROM TRYPTIC HYDROLYSATES OF BETA-CASEIN
BITTER TASTE OF ENZYMATIC HYDROLYSATES OF CASEIN .1. ISOLATION, STRUCTURAL AND SENSORY ANALYSIS OF PEPTIDES FROM TRYPTIC HYDROLYSATES OF BETA-CASEIN
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DOI：
10.1007/bf01202693
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发表时间：
1993-07-01
期刊：
影响因子：
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通讯作者：
BELITZ, HD
中科院分区：
文献类型：
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作者：
BUMBERGER, E;BELITZ, HD
从一头纯合子奶牛的乳中分离出β-酪蛋白A2，并用胰酶对其进行酶解。用反相高效液相色谱分离得到18种多肽，根据氨基酸组成，除1种多肽外，其余均为β-酪蛋白序列。一些多肽相互重叠。总体而言，它们代表了大约97%的蛋白质序列。只有I49-N68、I49-K97和G203-V209有苦味，I49-N68和G203-V209的识别阈值分别为1.0 mg/ml、0.45 mmoL/L、1.5 mg/ml、0.28 mmoL/L和0.175 mg/ml、0.23 mmoL/L。这三种多肽对β-酪蛋白水解物(2.67 mg/ml)的总苦味贡献率分别为11、21和60%。水解液中含有I49-K97多肽及其片段I49-N68和S69-K97。值得注意的是，较小和更疏水的片段I49-N68在摩尔基础上没有149-K97那么苦，而更大和更亲水的片段S69-K97具有中性味道。这些结果表明，在较大的多肽的情况下，疏水性和大小都不是苦味效力的单独原因，但构象参数肯定是非常重要的。此外，可以得出结论，只有结构的一部分负责与受体的接触。G203-V209的苦味结合文献中相关的合成肽进行了讨论。
Beta-Casein A2 was isolated from milk of a homozygous cow and hydrolysed with trypsin. The hydrolysate was separated by RP-HPLC into 18 peptides, all but one of which could be attributed to the sequence of beta-casein on the basis of the amino acid composition. Some peptides overlapped. In total, they represented about 97% of the protein sequence. Only three peptides had a bitter taste, namely I49-N68 (recognition threshold 1.0 mg/ml, 0.45 mmol/l), I49-K97 (1.5 mg/ml, 0.28 mmol/l) and G203-V209 (0.175 mg/ml, 0.23 mmol/l). The contribution of the three peptides to the overall bitterness of the beta-casein hydrolysate (2.67 mg/ml) was about 11, 21, and 60%, respectively. Peptide I49-K97 was present in the hydrolysate together with its fragments I49-N68 and S69-K97. Remarkably, the smaller and more hydrophobic fragment I49-N68 was less bitter than 149-K97 on a molar basis, whereas the larger and more hydrophilic fragment S69-K97 had a neutral taste. These results show that in the case of larger peptides neither hydrophobicity nor size are responsible alone for bitter potency, but that conformational parameters must be of great importance. Furthermore, it can be concluded that only a part of the structure is responsible for the contact with the receptor. The bitterness of G203-V209 is discussed in connection with related synthetic peptides in the literature.