Studies On Technology For Explosion Puffing Of Apple Slice At Low Temperature And High Pressure

The technology of puffing with low temperature and high pressure, which began to be studied overseas in 1980s, was usually used to produce puffed fruit and vegetable. The earliest study in China was reported in 1990s. But the systematic study on process and mechanism of puffing was lack. In this paper, several varieties, of apple were puffed in the puffing equipment (QDPH10-1) to optimize the puffing process, aiming at to supply technologies for producing puffed apple chips.The researched contents in this paper as follows: (1) pretreatment of apple slices, including blanching in water with different temperatures and immersing in several salt slutions;(2) studies on the technological parameters based on the effects on the product's quality;(3) optimization of the technological parameters;(4) studies on other factors affecting the product's quality. Conclusions can be summarized as follows:1. After pre-experiment, the technics of color protecting and pre-drying were immersing in 0.02% NaHSO₃ for 15min and drying 2h at 80°C respectively.2. The technique parameters by mono-fators experiment were determined as follows: apple slice's thickness is 5mm, water content before puffing is 30%, puffing temperature is 105°C, puffing pressure is 0.3Mpa, vacuum drying temperature is 80°C, and vacuum drying time is 30 min.3. The optimization technology parameters through central component rotatable design (CCRD) were apple slice's thickness is 3mm—4mm, vacuum drying temperature is 83°C⁸9°C, and vacuum drying time is 35min⁴5min. On these conditions, the product's crispness would below 1.0s with 95% possibility.4. After further study on other factors affecting apple's quality, it's found that the flavor of GuoGuang after puffing was better;irradiation and the treatment of maltose immersing was disadvantage at the improvement of puffed product's quality, however, freezing was advantage at the improvement of puffed product's quality;when the puffed product's water content exceeded 7%, the crispness and hardness of puffed product would not be good.