粒径对覆盆子粉体发酵乳品质的影响

Effect of Raspberry(Rubus idaeus L.)Powders with Different Particle Sizes on the Quality of Fermented Milk

为探究发酵乳添加覆盆子粉体后的品质变化,本研究采用机械粉碎结合行星球磨仪制备8种粒径范围的覆盆子粉体,研究不同粒径粉体对发酵乳发酵特性、质构、活性成分含量等的影响,分析发酵特性与乳体中活性成分的关联性,并表征覆盆子粉体的水合特性及其表面化学特征。结果表明,添加覆盆子粉体对发酵乳的可滴定酸度、pH值和乳清析出率无显著影响(P>0.05),且可提高发酵乳的持水能力、增强或稳定发酵乳的凝胶结构和三维网络、改良乳体质构等,从而提升发酵乳的品质;同时,发酵乳中还增加了总酚、黄酮等活性成分,其含量随粉体粒径的减小而增加,与粉体的傅里叶变换红外光谱分析结果相一致;此外,发酵乳的持水能力和乳清析出率与粉体总酚释放量呈显著正相关(P<0.05),而与粉体水合特性无相关性。以[150,200)目覆盆子粉体改善发酵乳品质效果较好,且其释放的活性成分含量较高。本研究结果可为覆盆子的加工利用及相关产品开发提供新思路。

To investigate the quality changes of fermented milk after addition of raspberry powder,eight raspberry(Rubus idaeus L.)powders with different particle sizes were prepared using mechanical pulverization combined with a planetary ball milling.The influence of different particle sizes on the fermentation characteristics,texture,and active ingredient content of the fermented milk were studied.The correlation between fermentation characteristics and active ingredients in fermented milk was analyzed,as well as the hydration and surface chemical characteristics of raspberry powder.The results found that addition of raspberry powder had no significant effect on the titratable acidity,pH and whey release rate of the fermented milk(P>0.05),but increased the water holding capacity,reinforced or stabilized its gel structure and three-dimensional network and improved the texture,thereby promoted the quality of fermented milk.In addition,the active components,including total phenolics and flavonoids in the fermented milk increased with the decreasing of the powder particle size,which was in line with the FTIR analysis of raspberry powders.Furthermore,the water holding capacity and whey release rate of the fermented milk were positively correlated with the total phenols release of the powder(P<0.05),but had no correlation was found to its hydration properties.In conclusion,raspberry powder with a particle size of[150,200)mesh exhibited the best improvement on the quality of fermented milk,and the active compounds releases from raspberry in the fermented milk were also high.This study can provide some new insights for the processing and utilization of raspberry and the development of raspberry-related products.