配餐食品中绿叶蔬菜的护绿保脆工艺优化

Optimization of Processing Technology to Maintain Green and Firmness of Green Leafy Vegetables in Bento

为解决配餐食品中绿叶蔬菜在较高温度(≥60℃)保存下变黄发软的问题,提出了一种护绿保脆工艺。首先,通过单因素试验探究碳酸氢钠浓度、抗坏血酸钙浓度、漂烫时长、氯化钙浓度、氯化钙浸泡时长对绿叶蔬菜色泽和硬度的影响,然后采用因子设计筛选出碳酸氢钠浓度、漂烫时长和氯化钙浓度为显著性因素,最后应用中心组合响应面法优化工艺条件。结果表明,最佳工艺条件为:碳酸氢钠浓度0.4%(m/m),抗坏血酸钙浓度0.01%(m/m),漂烫时长50 s,氯化钙浓度0.1%(m/m),氯化钙浸泡时长35 min。常见的四种绿叶蔬菜在最佳工艺条件下高温保存4 h后,色差值Δa*均下降,最低降至-5.59±0.33,叶绿素保留率最高提升了170%,护绿效果在保温的前2 h尤为明显,而两种绿叶蔬菜的硬度有所提高,最高提升至47.49±1.67 N,总体感官品质良好。此工艺能有效维持绿叶蔬菜的绿色色泽和较脆的口感,为配餐食品中绿叶蔬菜的加工提供重要的技术支持。

In this study,a processing technology to preserve green color and firmness was developed to solve the quality problem of blanched green leafy vegetables during thermal storing(≥60℃.Firstly,the effects of sodium bicarbonate concentration,calcium ascorbate concentration,blanching time,calcium chloride concentration and immersing time on color and hardness of blanched green leafy vegetables were studied by single factor experiment.Secondly,factorial design was applied to select significant factors,including sodium bicarbonate concentration,blanching time and calcium chloride concentration.Finally,the processing conditions were optimized by response surface based on central composite design.The results showed that the optimal processing conditions were as follows:sodium bicarbonate concentration of 0.4%(m/m),calcium ascorbate concentration of 0.01%(m/m),blanching time of 50 s,calcium chloride concentration of 0.1%(m/m)and immersing time of 35 min.The optimal conditions were validated by four kinds of common green leafy vegetables.After thermal storage for 4 h,all color differenceΔa*decreased and the lowest one was-5.59±0.33,the highest retention rate of chlorophyll was 170%,this effect was most significant 2 hours before preservation.The firmness increased in two kinds of common green leafy vegetables,the highest firmness reached 47.49±1.67 N.All green leafy vegetables showed good sensory quality under the optimal conditions.This processing technology can preserve the color and firmness of blanched green leafy vegetables effectively.The optimal processing conditions can provide important technical support for the processing of green leafy vegetables in bento.