Structural and textural characteristics of reduced-fat cheese-like products made from W1/O/W2 emulsions and skim milk

The chemical composition, yield, structural arrangement, instrumental textural characteristics, and preference sensory evaluation of reduced-fat cheese-like products manufactured from skim milk and different water-in-oil-in-water (W₁/O/W₂) emulsions were determined. A full-fat white fresh cheese (WFC) was prepared from milk containing 27 g of milk-fat L⁻¹, and five reduced-fat white fresh cheese-like products (EC) were made from skim milk added with 25 g of multiple emulsions L⁻¹ containing canola oil and stabilized/emulsified by amidated low-methoxyl pectin (LMP), carboxymethylcellulose (CMC), gum Arabic (GA), and blends of GA-CMC or GA-LMP. The chemical composition, yield, structural arrangement and texture of the cheese-like products were affected by the biopolymers used as emulsifying/stabilizing agents of the multiple emulsions. CMC produced an EC with similar textural behaviour than the WFC cheese. GA contributed to a higher yield and fat content in the EC cheese in comparison with CMC and LMP cheese. GA and LMP contributed to increased values of hardness and chewiness of the EC cheese. The cheese made with multiple emulsions incorporating GA and LMP emulated best the textural characteristics of the WFC cheese. All of the EC cheese showed marked differences in microstructure.     

负载姜黄素/花色苷的木薯淀粉基W1/O/W2型Pickering双重乳液的制备及性质

以木薯纳米淀粉、木薯醋酸酯变性淀粉为颗粒乳化剂制备食品级W₁/O/W₂型Pickering双重乳液,分别于内层水相、油相对姜黄素与花色苷进行负载。考察不同木薯醋酸酯变性淀粉质量分数对双重乳液显微形态、粒径、Zeta电位、负载率及贮藏稳定性的影响,并分析其在体外消化过程的控释性能。结果表明,木薯醋酸酯变性淀粉质量分数为6%时,乳液综合性能最好。此时,乳滴分布均匀,呈“三相两膜”结构,粒径为3.65μm,Zeta电位为-14.50mV,姜黄素、花色苷的负载率达到95.23%、93.00%,4、25、40℃时贮藏20d均未出现明显分层;经模拟消化后乳液中姜黄素、花色苷保留率为41.59%、76.29%,与游离姜黄素、花色苷相比,二者生物利用率分别提高了约4倍、3倍。证实了木薯淀粉基双重乳液能实现在模拟消化系统中对活性物质的保护,并能有效提升其生物利用率。研究结果旨在为食品工业中淀粉基功能性乳液运载体系的构建及新型食品级Pickering双重乳液的开发提供理论参考。     

Synergistic effects of whey protein–polysaccharide complexes on the controlled release of lipid‐soluble and water‐soluble vitamins in W1/O/W2 double emulsion systems

Lipid‐soluble vitamin E (V_E) and water‐soluble vitamin B₂ (V_B2) can be encapsulated together in the same water–oil–water emulsion system. The ability of whey protein isolate (WPI)–polysaccharide complexes to synergistically control the release rates in such a system was investigated. The complexes studied were WPI–low methoxyl pectin (LMP) and WPI–κ‐carrageenan (KCG). The encapsulation efficiency of V_E and V_B2 of the WPI system is 66% and 64% and increases by about 1.4‐ and 1.2‐fold in the WPI–LMP and WPI–KCG complexes, respectively, which serve as selective non‐pH‐dependent barriers against enzyme attack. These complexes also greatly ameliorate the controlled release rates of both vitamins. The low‐charge LMP, with its multiple protein‐ and oil‐binding abilities, exhibits greater synergistic effects than the high‐charge KCG.