超高温瞬时灭菌对甜玉米基质型全营养特医乳剂品质的影响

Effects of ultra-high temperature instantaneous sterilization on the quality of sweet corn matrix-based total nutrition special medical emulsion

中文关键词:  超高温瞬时灭菌  甜玉米  特医食品  乳剂  营养品质  感官品质

英文关键词:ultra-high temperature instantaneous sterilization  sweet corn  special medical food  emulsion  nutritional quality  sensory quality

中文摘要:

      目的 评价135~140 ℃、5~10 s超高温瞬时(ultra-high temperature, UHT)灭菌对乳剂热敏性营养素、物理稳定性和色度及感官品质的影响。方法 通过分析灭菌前后甜玉米基质型特医乳剂中主要维生素、叶黄素、玉米黄素含量以及离心沉淀率、粒径分布、微观形貌、色度、感官评分等指标, 并与常规高温高压灭菌的影响进行比较, 明确UHT灭菌后甜玉米基质特医乳剂的品质变化。结果 所采用的UHT灭菌条件均可使乳剂达到商业无菌标准; UHT灭菌后, 乳剂中维生素C、叶黄素、玉米黄素的含量呈下降趋势, 但在135 ℃ UHT灭菌乳剂中维生素C的含量高于140 ℃ UHT灭菌乳剂, 135 ℃/5 s最大含量可达到灭菌前的69.70%; 维生素A和维生素E在135 ℃条件下含量增加、140 ℃条件下含量下降, 135 ℃ UHT灭菌乳剂中最大含量分别达到灭菌前的104.04%、115.00%。UHT灭菌后, 离心沉淀率显著增加, 其中135 ℃/5 s UHT灭菌乳剂离心沉淀率最小, 为12.65%; 小粒径颗粒与大粒径颗粒的含量均增加, 其中135 ℃ UHT灭菌乳剂小粒径颗粒含量较多, 并且整体体系比较均匀; 红值(a*)显著增加, 亮度(L*)、黄值(b*)无显著变化。综合各指标分析结果, 135 ℃/5 s灭菌条件下甜玉米基质型特医乳剂的营养与感官品质优于其他UHT灭菌条件, 且具有热负荷和能耗较低的优势; 相较于高温高压灭菌乳剂, 135 ℃/5 s UHT灭菌乳剂中维生素C、维生素A保留率分别增加了39.34%、13.32%; L*显著提高, 离心沉淀率、平均粒径及a*显著降低, 感官评分显著大于高温高压灭菌乳剂。结论 UHT灭菌有利于保留乳剂营养成分、提高其物理稳定性及感官品质。本研究可为UHT灭菌在农产品基质型特医乳剂食品中的应用提供参考。

英文摘要:

      Objective To evaluate the effects of ultra-high temperature (UHT) sterilization at 135–140 ℃ for 5–10 s on heat-sensitive nutrients, physical stability, chromaticity and sensory quality of emulsions. Methods By analyzing the content of the main vitamins, lutein and zeaxanthin in the sweet corn matrix special medical emulsion before and after sterilization, as well as the indicators such as the centrifugal precipitation rate, particle size distribution, microscopic morphology, color intensity and sensory score, and comparing them with the effects of conventional high-temperature and high-pressure sterilization, the quality changes of the sweet corn matrix-based total nutrition special medical emulsion after UHT sterilization were clarified. Results All UHT sterilization conditions could make the emulsion reach the commercial aseptic standard. The content of vitamin C, lutein and zeaxanthin in the emulsion sterilized showed a decreasing trend, but the vitamin C content of 135 ℃ UHT sterilization emulsion was higher than 140 ℃ UHT sterilization emulsion, and the maximum content could reach 69.70% of unsterilized emulsion at 135 ℃/5 s. The content of vitamin A and vitamin E increased at 135 ℃ and decreased at 140 ℃, and the maximum content of 135 ℃ UHT sterilization emulsion reached 104.04% and 115.00% of unsterilized emulsion, respectively. The centrifugal precipitation rate of UHT emulsion increased significantly after sterilization, and the 135 ℃/5 s UHT emulsion was the smallest, which was 12.65%. Both the content of small size particles and large size particles increased after sterilization, and the content of small particle size was more in 135 ℃ UHT sterilization emulsion, and the whole system was relatively uniform. The red value (a*) increased significantly, while the brightness (L*) and yellow value (b*) did not change significantly. In conclusion, the nutritional and sensory quality of sweet corn matrix special medical emulsion under 5 s sterilization at 135 ℃ was better than other UHT sterilization conditions, and had the advantages of lower heat load and energy consumption. It was found that the retention rates of vitamin C and vitamin A in the 135 ℃/5 s UHT sterilization emulsion were significantly increased by 39.34% and 13.32%, respectively. The L* was significantly increased, the centrifugal precipitation rate, the average particle size and the a* were significantly decreased, and the sensory score was significantly higher than that of high temperature autoclave emulsion. Conclusion UHT sterilization is beneficial to retain the nutrients of the emulsion, improves its physical stability and sensory quality. This study can provide reference for the application of UHT sterilization in the special medical emulsion of agricultural products.