Research On Snack Food Of Pleurotus Eryngii And Pleurotus Ostreatus

The edible fungi is a kind of macro-fungus with fleshy fruitbody and sclerotium organization, it have delicious flavor、comprehensive nutrition and can play important role in improving the dietary structure and extending human life, has been hailed as " healthy food in 21st century" by FAO. The edible fungi in china is in large quantities and occupy over 70% of the world, at present, the mainly consumption patterns of the edible fungi is being eaten fresh, it is perishable and can not easily be preserved because of the high moisture content, therefore causing great waste. As the increasing consumer demand of the edible fungi, the processing of the edible fungi is imminent.In this article, the ultrasonic immersion and vaccum-microwave drying technologies were mainly used, the processing and flavouring formulas of the snack food of Pleurotus eryngii and Pleurotus ostreatus were mainly studied. Under laboratory conditions, non-fried Pleurotus eryngii chips、 Pleurotus ostreatus puffed chips and flavored Pleurotus ostreatus stem crumb had been developed, some physical -chemical index and sensory quality of these three products had been analyzed and evaluated.The detailed contents comprised the following three aspects.1. Development of non-fried Pleurotus eryngii chips. Pleurotus eryngii was selected as the raw material, the Pleurotus eryngii was cutted and immersed in 15-fold volume of maltodextrin solution assisted by ultrasonic, and dehydrated by using vacuum microwave drying to produce a kind of non-fried Pleurotus eryngii chips,the drying conditions were:600W、 15min,then 700W、8min. With the immersion ratio, hardness, tenacity and color of the products as measure indicators for optimizing the ultrasonic-assisted impregnation process with orthogonal experimental method. The results showed that different ultrasonic immersing conditions could significantly affect the efficiency of immersion, hardness, tenacity color and sensory quality of the products, The optimal ultrasonic immersing conditions for best sensory quality of Pleurotus eryngii chips were immersion temperature of 55 ℃, maltodextrin concentration of 15%, and ultrasonic immersion time of 20min. Under the optimized conditions, the immersion efficiency of maltodextrin was 0.29%, and the hardness, tenacitity and the L* of the products were 2115.21/g,114.44 J/cm2 and 76.02, respectively. The products had the characteristics of uniform shape、 light yellow color and crispy taste, and the sensory score was the best. Therefore, the ultrasonic immersion process could be preferred to produce high-quality Pleurotus eryngii chips.2. Development of Pleurotus ostreatus puffed chips. Pleurotus ostreatus was selected as raw material,immersed in 5% aqueous maltodextrin solution, to establish a kind of Pleurotus ostreatus puffed chips through the main technical process of cooking、 hot-air predrying、vacuum-microwave drying. Optimization of vacuum-microwave drying technology for Pleurotus ostreatus chips has been mainly studied. Using the expansion ratio, sensory score as measure indexes, on the basis of single factor test for the effects of the water content of the pre-dehydrated Pleurotus ostreatus, microwave power and heating time on the qualities of the Pleurotus ostreatus chips prepared by vacuum-microwave drying, The conditions of vacuum-microwave technology puffing Pleurotus ostreatus chips were optimized by response surface methodology(RSM) design.The optimum vaccum-microwave drying conditions were determined as following:the moisture content of the pre-dehydrating Pleurotus ostreatus was controlled at 44%, microwave power was 710 W,microwave heating lasted for 9.9minutes with the vacuum pressure of 0.08 MPa. The hardness of the product was 1201.4/g,it had the characteristics of complete shape、uniform color and crispy taste, and the sensory score was 93.42. Therefore, the vacuum-microwave drying process could be preferred to produce high-quality Pleurotus ostreatus chips.3. Development of flavored Pleurotus ostreatus stem crumb. With fresh Pleurotus ostreatus stem as raw material, to establish a kind of flavored Pleurotus ostreatus stem crumb through the main technical process of soaking for softening、 precooking、predrying and frying.The optimum technologic parameters of processing and the amount of different flavors material have been studied through the single factor and orthogonal experiment. The optimum conditions were determined as following:soaking 3h with 5.0% NaHCO3 aqueous solution; cooking the shredded Pleurotus ostreatus stem 10 minutes in the 100 ℃ and then 30 minutes in the 80℃; combined drying method was adopted, obtained the moisture content at 40.00±1% with vaccum-microwave drying under 500W and then with hot-air drying under 50 ℃ to obtain a certain moisture content;the optimal moisture content of the pre-drying shredded stem was controlled at 16.00±1%; frying the shredded stem 10 minutes at the 300W and then 20 minutes at the 100W.The best ingredients for cooked process was:the ratio of material to solvent was 1:5, on the 100g fresh weight basis of pleurotus ostreatus stem, Sichuan pepper 0.6 g, sugar 6.0 g,salt 2.0 g, monosodium glutamate 1.1 g; the best ingredients for frying process was:5 ingredients pine 4 g, cooking oil 3.5 g, rice wine 4.0 g, salt 1.0 g, monosodium Glutamate 0.5 g.The product is in golden color, chopped or flocculent in shape and delicate taste, have good chewy and pleasant flavor, and with shredded mushroom, the moisture content in 9.0-10.0%, the qualities is good.