Research on Fermentation Technology of Raspberry-mulberry Leaven

The mixed fermentation is based on the raw material of raspberry and mulberry. The research is to explore the sticking point for the fermentation progress. To attain the optimized fermentation condition which gained by integrating fermentation data,the concentration of pectinase should be 80 mg/L,the mass fraction of Lactobacillus,Acetobacter and yeast should be 3%,1% and 3%,respectively,the fermentation temperature should be 28 ℃,the initial sugar content should be 24°,and the duration of fermentation should be 16 d. After the fermentation,sugar content should be adjusted to 25°,and the products should be stored for 3 d in the condition of 15 ℃. The Raspberry-mulberry leaven containing 8. 5 × 10;probiotics per milliliter and 61. 2 g total acid per liter should be diluted with various proportions of water to drink according to different habits of customers[1]. The volume ratio of leaven and water should be at least 1∶ 1 and at most 1∶ 3.

Effects of Different Extraction and Purification Methods on the Acquisition of Phycoerythrin from Porphyridium purpureum

Phycoerythrin, as the main light-harvesting antenna in Porphyridium purpureum, exists at the outermost end of the phycobilisome. It has advantages of good fluorescence intensity, anti-oxidation, scavenging free radicals, and high chroma, so it has been widely used in food, cosmetics, pharmaceuticals, and other industries. In this study, the effects of different extraction(ultrasonic breaking method, bead grinding method, liquid nitrogen grinding method, and freezing-thawing method) and purification methods(salting out method, ultrafiltration method, and combination of salting out and ultrafiltration method) on the acquisition of phycoerythrin from P. purpureum were studied, and the characteristics of phycoerythrin in the P. purpureum were identified. The results showed that the freezing-thawing method could extract phycoerythrin from the powder of P. purpureum to the utmost extent, and the concentration of the extracted phycoerythrin was up to 0.036 g/L. The salting out method could most effectively purify phycoerythrin, and the purity index was 2.216. The identification of phycoerythrin by ultraviolet absorption spectroscopy and fluorescence spectroscopy indicated that the phycoerythrin had the maximum absorption peak at 545 nm, and the maximum Stokes shift was up to 79 nm. Due to its high fluorescence characteristics, it can be used as a fluorescent marker in the fields of molecular biology and clinical medicine, and can also be used as a good photosensitizer in tumor therapy.