| Pumpkin (Cucurbita moschata) is the fruit of cucurbitaceous plants. It is annualherb plants and widely planted in China. Pumpkin flesh is the part between thepumpkin pulp and the seeds. It is also the essential parts that pumpkin seeds growmature and rely on, which also presents a silk pulp shape. In the processing ofpumpkin, almost all of them are abandoned and wasted. Yet few literature reported forits research. Pumpkin flesh, which is rich in pigments and nutrients and close to thepumpkin pulp, contains a certain amount of cryptoxanthin. By ultrasonic andmicrowave assisted method, the experimets attempt to extract cryptoxanthin from thepumpkin flesh and optimize the processing in this paper. Purification and stability ofcryptoxanthin were studied. Results are as follows:1. Finally chose ethanol as the organic solvent from methanol, ethanol, acetoneand n-hexane. The selection test included Volume fraction of ethanol (V/V),temperature (℃), the material liquid ratio (g:mL), ultrasonic power(W), ultrasonicaction time. Ultrasonic action time30minutes are the best choice. The responsesurface experiment was carried out and optimized by the software named DesignExpert, which selected temperature (℃), the material liquid ratio (g:mL), ultrasonicpower (W) as the main single factors. The significance order that the factors impacton the absorbance value was as follows: temperature> solid-liquid ratio> ultrasonicpower. The best optimization results were that Temperature of38.6℃, the materialliquid ratio of15.7(g:mL), supersonic wave power of135.4W.2. Still using ethanol as the organic solvent, the experiments selected temperature,microwave frequency, microwave power, microwave action time, and solid-liquidratio as influencing factors. The experiment result was better with a condition ofmicrowave action twice, the action time60s. Select microwave power, microwaveaction time, and solid-liquid ratio as three single factors to optimize the processingconditions by response surface methodology. The optimal process results were thatmicrowave power of202.5W microwave action time of60s material liquid ratio of15.7（g/mL)。 3. Aspects of Temperature, light, pH, common food additives，metal ions,resistance to oxidation and reducing have been studied to influence of the remainingrate of cryptoxanthin. The results were as follows: cryptoxanthin basically stabilize atroom temperature, while it was damaged at the temperature higher than40℃. Whenthe temperature was above60℃or more than80℃, it was almost entirely destroyed.Cryptoxanthin is sensitive to light and has the poor stability under acid condition andgood stability in alkaline condition. Benzoic acid had a destructive effect oncryptoxanthin while other common food additives could coexist with it. It has a goodcoexistence with metal ions of iron, copper, aluminum and poor relationships withmetal ions of sodium, potassium, magnesium, calcium. Cryptoxanthin has certainresistance to anti-oxidation and reducing power. |
