Study On The Fermentation Process Of Sweet Corn And Milk By Lactic Acid Bacteria

Sweet corn is cultivated by the technology of transmit gene. Sweet corn is one of the most important vegetables in the USA. The total production values of sweet corn are fourth in fresh vegetable selling. The climate is also very fit for cultivating sweet corn in China. In assumable statistic, the areas of cultivating sweet corn are 266.7 thousand hectare. But there are only few kinds of sweet corn production modalities, the processing methods are backward and the attached value to the products is very low at present. So the common concerns of the food researchers and the consumers are: how to diversify the product types of sweet corn, increase the quality of sweet corn products. The sweet corn yogurt is made of sweet corn and milk through lactic acid fermentation, this product encompasses advantages of the health beneficial function of sweet corn and lactic acid bacteria. It should be a new way to the processing and utilizing of the sweet corn resources.This paper mainly discusses to prepare a nutritious and well-gelatinized and fermented sweet corn beverage, with sweet corn being the material. Sweet corn liquefied with a-amylase along with a proper amount of cow milk and fermented with lactic acid bacteria, then the product was coming to being. The optimal conditions of pulping sweet corn juice; liquefying sweet corn syrup; fermentation processing of sweet corn and milk; the stabilizing reagent were confirmed.The experiment testifies as followings:1. The optimal parameters of pulping sweet corn juice is: sweet corn and water is 1:4(w/w), pulped at 60℃for 1 min, the soluble compositions and soluble protein of sweet corn syrup both reached themaximum contents: 2.1°Bx and 0.38g/100mL.2. The optimal condition to hydrolyze sweet corn syrup is: sweet corn : water is1:4(w/w), time is 60 min, temperature is 90℃, enzyme quantity is 0.10mL/100g. Under this condition, the soluble composition reached 3.2°Bx, and DE value reached 3.50, both in high level.3. Utilized the Lactic Acid Bacteria which were tamed at the volume proportion of the sweet corn syrup and milk was 7:3, then enlarged as starter, the amount of L bulgaricus and Str. thermophilus were 6.9×10~7cfu/mL and 9.2×10~7cfu/mL respectively. 4. The stabilizing reagent, homogenization and sterilization technology of the mixture also influenced the stability and taste greatly. The experiment result shows after we added 0.20%PGA+0.10% to the compound, then was homogenized at 25～30MPa, and being sterilized for 15rain, at 100℃, the product would be better in stability.5. This research set the fermenting temperature, inoculating quantity, adding varieties of sugar, proportion of the bacteria seed, and the fermenting time based on the single-factor experiment. The optimum condition of the sweet corn and milk fermentation is that: adding 3% sugar (saccharose: glucose=1:1), and the bacteria inoculum 5% at 43℃for 10 hours.