关键词: 马铃薯方便粥；气流膨化；品质；微观结构；变异系数法

Abstract: In order to explore optimal air puffing conditions for instant potato congee, the effects of different air puffing treatments on the nutritional components, color difference, texture characteristics, rehydration characteristics and volatile aroma components of instant potato congee were studied by combining physicochemical analysis techniques with colorimeter, texture analyzer and gas chromatography-mass spectrometry (GC-MS). Furthermore, a comprehensive quality evaluation was carried out. The results showed that suitable air puffing treatment could reduce moisture content and well preserve the color, total dietary fiber and soluble dietary fiber of potato congee. It also could shorten the rehydration time, improve the rehydration ratio and impart roast nut-like aroma, burnt aroma and the unique aroma of edible tubers to instant potato congee. Based on variation coefficients, water content, volatile aroma components (heterocyclic compounds, aldehydes, hydrocarbons) contents, chewiness, hardness, and rehydration time accounted for a larger proportion of the overall evaluation. The results of the comprehensive evaluation showed that the quality of the potato congee treated at 130 ℃ for 50 s was the best. Scanning electron microscopy (SEM) results showed that potato congee exhibited a porous network structure after air puffing treatment, and the internal structure became swollen and loose. The infrared spectroscopic result showed that the molecular configuration of protein and starch was affected by air puffing treatment. It is concluded that appropriate air puffing treatment could improve the quality of potato porridge and shorten the rehydration time.

Key words: instant potato congee; air puffing; quality; microstructure; coefficient of variation