【作者】 王树林；

【导师】 陈有亮；

【作者基本信息】 浙江大学 ， 食品科学， 2003， 硕士

【摘要】 果料乳制品生产已成为乳制品工业的发展趋势。由于各种原因，国内果料乳制品的生产仍处于初级阶段，且在生产技术上存在诸多问题。本研究从产品配方和工艺着手，探讨了影响果料乳制品产品稳定性和感官质量的因素；采用正交二次旋转设计和正交设计筛选了产品的最佳配方和工艺，取得了大量的基础试验和生产数据，为此类产品的生产提供了理论依据。主要研究结果如下： 1．橙汁和有机酸的添加可使牛乳及橙汁乳体系的稳定性下降，蛋白质沉淀。橙汁添加量达到24％时，牛乳中蛋白质的沉淀显著增加，稳定性明显降低；当有机酸的添加使牛乳和橙汁乳体系的pH达到5.11(牛乳)和5.16(橙汁乳)以下时，体系的稳定性显著下降。虽然牛乳和橙汁乳的pH下降随有机酸添加量的增加并不同步，但稳定性的下降随体系酸度的升高具有相同的趋势。 2．稳定剂的添加在一定程度上可防止酸性乳(pH=5.30-5.35)体系牛乳蛋白的沉淀，CMC-Na与PGA的使用比例为3：4，磷酸盐的使用量为0.03％时，牛乳的沉淀率最低，牛乳蛋白最稳定。考虑到CMC-Na的增稠作用，为使产品具有较为清爽的口感，适当降低CMC-Na使用比例，建议在实际生产中将CMC-Na与PGA的配比定为2：3。产品的稳定性与稳定剂的使用量之间不存在正的直线相关关系；液态橙汁乳中添加0.02％的蔗糖酯和0.06％的分子蒸馏单苷酯可有效防止产品分层。 3．经过正交二次旋转试验和正交试验确定的液态橙汁乳最佳配方为：橙汁11.5％，有机酸0.17％，白砂糖3％，稳定剂(CMC-Na：PGA=2：3)0.17％，磷酸盐(多聚磷酸盐：焦磷酸盐=1：1)0.24％，蔗糖酯0.02％，分子蒸馏单苷酯0.06％，牛乳76.42％水8％，脱脂乳粉0.64％。 4．液态橙汁乳的关键性生产工艺，如原料乳的杀菌、混合物料的均质、混合物料的酸化、产品最终的杀菌都会对产品的稳定性有影响。产品原料乳的杀菌应采用高温短时杀菌；橙汁及有机酸的添加应在混合物温度降低到30℃以下后进行；原料乳的均质有助于产品稳定性的提高，但混合物料的均质对产品稳定性没有明显提高，因而均质工艺仅限于对原料乳的均质，对混合物料则无须均质。 5．搅拌型橙汁酸乳的最佳配方为牛乳60％、脱脂乳粉1.6％、白砂糖8％、浙江大学硕[:学位论文橙汁添加量12%、水18%、CMC一Nao.3%和PGAO.l%。 6.搅拌型橙汁酸乳生产的关键工艺参数为:原料乳的杀菌条件90℃，7min;发酵温度38℃，发酵时间为4.5h;原料乳的均质条件30℃，10MPa。 7.在液态橙汁乳和搅拌型橙汁酸乳研究的基础上进一步探讨了甜酒酿酸乳饮料和搅拌型草墓酸乳的生产技术。甜酒酿酸乳饮料的最佳配方为CMC一a0.375%，PGA 0.125%;牛乳55%，白砂糖6.巧%，水15.28%，橙汁7.69%和甜酒酿巧28%。首先生产纯酸乳，然后加入稳定剂、果汁和甜酒酿进行均质(10Mpa)加工生产甜酒酿橙汁酸乳饮料。 8.搅拌型草葛酸乳配方中的主要配料为:稳定剂(CMC一Na:PGA=3: 1)4%，草墓浆的添加量在25一20%。更多还原

【Abstract】 The products of fruits dairy have become one trend of dairy industry. In our country, the productions of these dairy products still were in beginning as some problems. The stability is one of the most prominent problems, which can be solved through adding stabilizers and improving technology. The facts of influencing stability and esthetic quality of the products have been studied in this paper. The main results were summarized as follows:1. The additions of orange juice and organ acid had destroied the stability of milk and the protein had been precipitated.2. The stabilizers and emulsions can help to improve the stability of products; the optimum using rate of CMC-Na and PGA was 3:4 in orde to restrict the precipitation of milk; and considering the negative effect of CMC-Na to the sense of mouthful of products, the optimum rate of CMC-Na and PGA should be 2:3. There was not linear relationship between the stability of products and the increase of stabilizer. 0.02% of sucrose esters of fatty acids and 0.06% of distilled monoglycoride have effect to restrict the separation of products.3. The technology has distinct influence on the stability of milk of orange juice. The pasteurization of milk should use ultrahigh temperature (UHT); the orange and acid shoud been added after the mixtures had been cooled to 30 癈 so to avoid the coacervation of proteins. The raw milk shoud be homogenized so to improve quality of product and avoid separation of milk fat and the mixtures did not be homogenized, which no effect to improve the stability of product.4. The optimum formula of milk of orange juice has been screened through the second orthogonal rotating experiment design. The optimum formula was as follow: 11.5% of orange juice; 0.17% organ acid;3% of white sugar; 0.17% of stabilizer(CMC-Na:PGA=2:3); 0.24% of phosphate(sodium polyphosphate: sodium pyrophosphate = 1:1); 0.02% of sucrose esters of fatty acids, 0.06% of distilled monoglycoride; 76.42% of milk; 8% of wate; 0.64% of skim milk powder.5. The foundation of production of stirred orange juice-yoghurt is the processing of set yoghurt. The optimum formula of stirred orange juice-yoghurt was as follow: 60% of milk; 1.6% of skim milk power;8% of white sugar; 12% of orange juice; 18% of water; 0.3% of CMC-Na; 0.1% of PGA; and the optimum processing was as follow: the raw milk was pasteurized under 90 for 7min; the raw milk was homogenized under 30 , 10Mpa ;and incubated under 38 for 4.5h.6. The yoghurt beverage of orange juice-tianjiuniang and the stirred strawberry yoghurt was researched under the works of abover. The result showed: the optimum formula of the yoghurt beverage of orange-tianjiuniang was as follow: 0.375% of CMC-Na; 0.125% of PGA; 55% of milk;6.15% of white sugar ; 15.28% of water; 15.28% of tianjiuniang and 7.69% orange juice. The set yoghurt was produced and then the yoghurt beverage of orange-tianjiuniang was produced through adding stabilizers (stabilizers, water and white sugar) and homogenizing the mixture under lOMpa.The optimum formul of the stirred strawberry yoghurt was 4%(CMC-Na: PGA=3:1) of stabilizers and 20-25% of strawberry.更多还原