On Comprehensive Utilization Of Hazelnut

The present experimentt investigates the technological conditions for extractionof hazelnut oil, analyses the fatty acid composition of the oil, evaluates effect ofhazelnut processing, and studies the manufacturing technique of hazelnut proteinbeverage with hazelnut meal.Hazelnut oil was extracted, respectively, with three oil extraction methods:soxhlet extraction, solvent extraction, and cold processing. Hazelnut oil yield as thereference index, the optimum extraction efficiency for each method was investigatedwith single factor and orthogonal design test. The following results were obtained.The optimum conditions for soxhlet extraction of hazelnut oil were: extractionsolvent/material ratio,11mL/g; temperature,76℃; extraction time,4h. Hazelnut oilyields from roasted hazelnut and unroasted hazelnut were63.7%and62.4%,respectively. The optimum technological conditions for solvent extraction of hazelnutoil were: extraction time8h, extraction solvent/material ratio,11mL/g;volume/quality ratio,22mL/g. The oil yields from roasted hazelnut and unroastedhazelnut were61.8%and59.6%, respectively. The optimum conditions for extractionof hazelnut oil by cold squeezing were the conditions modulated by the oil pressmanufacturer. The oil yields from roasted hazelnut and unroasted hazelnut were60.0%and59.3%, respectively.Hazelnut oil was esterified using the method “preparation of methyl esters offatty acids in animal and vegetable fats” described in GB/T17376-17376, and thenwas extracted for GC/MS analysis. The influence of the different processing methodson hazelnut yield efficiency was explored and the fatty acid composition and contentwere measured. The results showed that:(1) after hazelnut was roasted oil yieldincreased by0.7%, saturated fatty acid increased by3.76%, monounsaturated fattyacid decreased by2.86%, polyunsaturated fatty acid decreased by0.98%, and15-methyl-11-hexadecenoicate and methyl heptadecanoicate were newly found,(2)oil yield by chemical extraction increased by3.7%as compared with cold squeezing method, saturated fatty acid decreased by8.70%, the oil had3.55%higher singleunsaturated fatty acid and5.28%higher polyunsaturated fatty acid. Methylmyristicate and methyl-13-cis-docoseniocate lost, and methyl-7,10-octadeca-dienoicate appeared.Hazelnut protein beverage was developed using hazelnut meal after oilextraction as raw material. Hazelnut meal was dried under80℃for12h, thenground, and sieved through100mesh to produce very fine hazelnut powder. Hazelnutpowder added with water was boiled, then filtered through a cloth filter, and separatedhazelnut milk from the residue. Hazelnut milk was used as the main material toproduce hazelnut protein beverage. The repeated test results showed that thestabilizing effect of the mixture emulsifying stabilizers was superior to that of singleemulsifier and stabilizer. The optimized formulation of emulsifying stabilizer wasestablished:0.05%of the compound emulsifier, the m(monoglycerides):m(sucroseesters): m(tween-80)=3:1:1; the value of HLB,8.88;0.53%of the compoundstabilizer, m(xanthan gum):m(guar gum):m(carrageenan)=4:1:0.3. By the orthogonalexperiment analysis, the optimum homogenizing conditions were obtained:60℃,fine grinding3min under2m of the fineness, then coarse grinding2min under10m of the fineness. Hazelnut protein beverage was sterilized undr high temperatureand high pressure. The proper sterilization conditions were determined ultimately as15min/121℃through comparing the different conditions.