Development of ice cream fortified with calcium and vitamin D3 emulsion

This study aimed to develop ice cream fortified with calcium and emulsified vitamin D3 using milk proteins as an emulsifier. Physicochemical stability of vitamin D3 emulsion using different milk protein emulsifiers including nonfat dry milk (NFDM), sodium caseinate (NaCN), and whey protein isolate (WPI) was investigated. Emulsion using NaCN had the smallest oil droplet size and the lowest creaming index throughout the storage time (P < 0.05). Then, vitamin D3 emulsified by NaCN was selected to fortify in regular fat (RF, > 10% fat), light fat (LF, < 5% fat) and fat free (FF, < 0.625% fat) ice creams at 250 IU per serving. Retention of vitamin D3 in each ice cream formulation was determined compared to control (non-emulsified vitamin D3) at day 0, 7, 14, 28 and 56 of storage at -20 °C. The results indicated that emulsified form of vitamin D3 remarkably improved vitamin D3 stability in all ice cream formulations. The ice creams were further fortified with 200 mg elemental calcium. Calcium content and vitamin D retention were investigated through 28-day storage. The results showed that both nutrients were preserved in the ice creams throughout the storage time. Physical characteristics and microbial properties of the ice creams were also determined. Overrun and viscosity of all ice cream formulations were not significantly different. Hardness and melting behavior increased with decreasing fat content. Aerobic bacteria were < 1,000 CFU/mL and no Escherichia coli and coliform were detected through 28 days. Our findings could be useful for the ice cream industries that seek to add vitamin D and calcium to their products.

本研究旨在开发以乳蛋白作为乳化剂，强化钙与乳化型维生素D3的冰淇淋产品。本研究探究了采用不同乳蛋白乳化剂——包括脱脂乳粉（nonfat dry milk, NFDM）、酪蛋白酸钠（sodium caseinate, NaCN）以及分离乳清蛋白（whey protein isolate, WPI）——制备的维生素D3乳液的理化稳定性。实验结果显示，采用酪蛋白酸钠制备的乳液在整个存储周期内油滴粒径最小，且乳析指数最低（P < 0.05）。随后，选取经酪蛋白酸钠乳化的维生素D3，分别添加至常规脂肪（regular fat, RF，脂肪含量>10%）、低脂（light fat, LF，脂肪含量<5%）以及无脂（fat free, FF，脂肪含量<0.625%）冰淇淋中，每份添加量为250 IU。以未乳化型维生素D3作为对照组，分别在-20℃存储第0、7、14、28及56天时，检测各组冰淇淋配方中维生素D3的保留率。结果表明，乳化型维生素D3可显著提升所有冰淇淋配方中维生素D3的稳定性。后续向上述冰淇淋中额外添加200 mg元素钙，并在28天存储周期内检测钙含量与维生素保留率。结果显示，两种营养成分在整个存储过程中均得到有效保留。本研究同时测定了冰淇淋的物理特性与微生物学特性：所有配方的膨胀率与黏度均无显著差异；硬度与融熔特性随脂肪含量降低而升高；28天存储周期内好氧菌总数均<1000 CFU/mL，未检出大肠杆菌与大肠菌群。本研究结果可为冰淇淋行业开发添加维生素D与钙的产品提供参考。