Study On Compound Walnut Milk Process And Quality Characteristics

Walnut milk which is extracted from plants is a natural beverage, the product is smooth tastes and pecial fragrance rich walnut. Walnut milk is relatively single and the development depth is not enough at present, it is difficult to reflect the walnut resources development advantages and meet the diversified demand. This topic is based on local specialty walnut, integration of other characteristics of agricultural resources, buckwheat, coix seed, green-tea,to research the new products of green-tea walnut milk beverage, buckwheat low-fat diet walnut milk, composite powder with fermented walnut dreg,in order to improve the added value and promote the local walnut industrial development to provide certain guidance and technical resources, the specific research and the results are as follows:1.Taking the walnut and green tea power as main raw materials,the processing conditions were studied by orthogonal teats and sensory evaluation.The results showed that the optimal formula of green-tea walnut milk was with 24% walnut juice, 0.3% green tea and 6%sucrose. And the product with good taste and flavor was obtained, whose best emulsifier(0.25%) for the beverage was monoglyceride and sucrose ester(2︰8) and its stability was most satisfactory with 0.15% xanthan gum, 0.3% CMC-Na and 0.1%beta-CD.2.This paper was studied to the producing technology of buckwheat low-fat low sugar walnut milk, taking walnut dregs and Buckwheat power as main raw material. The parameters of processing technology were determined through orthogonal tests and sensory evaluation. The results showed that the optimal formula of buckwheat low-fat low sugar walnut milk was with 28% walnut dregs juice, 1.5% Cooked buckwheat powder,3%sucrose and2.8% erythritol. And the product with good taste and flavor was obtained, whose best stabilizerfor the beverage was 0.10% xanthan gum, 0.07% CMC-Na and 0.08% sodium alginate.3.The buckwheat walnut milk, buckwheat hydrolysis walnut milk, and two kinds of walnut milk on market were studied about the vitro antioxidant clearing DPPH ?, ? OH, O2- ? capability, the results showed that the four kinds of walnut milk all have the ability to remove three kinds of free radicals, buckwheat walnut milk than buckwheat hydrolysis milk strong antioxidant capacity(P<0.05). Buckwheat walnut is equal to 0.483 mg/ml Vc solution in the removal ability of DPPH ?; The removal ability of ? OH is equal to 13.86 mg/ml Vc solution; The removal ability of O2- ? are equal to 2.52 mg/ml Vc solution.4.The lactic acid bacteria screening of fermented walnut pulp juice, the experiment with pH, acidity and sensory score as index combined with the fuzzy mathematics method, the 9 strains of LAB were selected find that the acidophilus and lactobacillus plantarum are the excellent strain.Through compound with LAB fermentation experiment,lactobacillus acidophilus:plant lactobacillus(1:1) inoculation amount to 3%, 38 ℃ fermentation conditions after 6 h to get the best hydrolysis fermentation juice comprehensive quality, its sensory score: 90.00, soluble solids:7.6%,acidity, 80 t, amino nitrogen, 57.0mg/L, living bacterium 7.35×107cfu/ml.5.This paper was studied to formulation and process of composite milk with fermented walnut dreg, through orthogonal test and sensory evaluation, the best formula for raw materials: hydrolysis fermentation juice 27%, coix seed powder 2%, sugar 4%, trehalose 2.23%, the product formula has the best color, flavor and stability of the organization, the product comprehensive score is 9.6 points; Through condition optimization in product best fermentation:38℃temperature,fermentation time of 6h, quantity of 3%, the fermentation product comprehensive score is 9.0 points.Taking the survival rate of LAB and solubility as main index, the protective screening were studied by Plackett- Burman method, the steepest climbing and Box-Benhnken Design experimental Design method, the results showed that the optimal formula of composite milk with fermented walnut dreg was with 2.23% trehalose, 2.5%dried skim milk and 2.77%maltodextrin, According to the formula to test,the product comprehensive score is 97.12, the survival rates of lactic acid bacteria was 85.1%, the sensory score 94.2; By the survival rate of LAB and set powder rate as an index, spray drying technology condition is obtained by the orthogonal experiment for: inlet temperature 160 ℃, the temperature 70 ℃, wind peristaltic pump speed 8 r/min, living bacterium rate of composite power with fermented walnut dreg was 85.4%, set powder at rate was 65.2%.Through the ultrastructural observation of composite powder with fermented walnut dregs found that without adding protective product particles is irregular, into squares, add protective agent sample particles is neat, spherical, particle surface with micro holes.The flavor substances of composite powder with fermented walnut dreg is a total of 32 species, with aldehydes mainly 13 species, alcohols, ketones, there are 14 kinds of the same flavor substances between composite milk with fermented walnut dreg and traditional fermented walnut milk, acetaldehyde is one of the main flavor substance; The content of aldehydes, alcohols, esters flavor substances in composite milk with fermented walnut dreg is significantly higher than the traditional fermented walnut milk, and the increase of flavor substances is phenol, furan, pyran, such as 2, 4-2 tertiary butyl phenol is a good antioxidant, the emergence of new flavor substances mainly related to the new starter cultures and badery coix seed powder.6. The results of composite powder with fermented walnut dreg: the living bacteria number of LAB 9.71×108 cfu/g, fat8.24%, dietary fiber 5.43%, water 2.44%, protein 9.74%, K value 0.040. According to the index about the total number of lactic acid bacteria fall, peroxide value(POV), strong stability and sensory score, we can find product quality changes by observation of accelerated shelf life test and reach a conclusion about shelf life of composite powder with fermented walnut dreg byQ10 model, the results show that product can be stored in 285 days under the conditions of temperature 25 ℃, 50% humidity preservation.