Effects Of Main Nutrient Source On Monascus Purpureus Secrete Pigment

Monascus can secrete manifold metabolic product with application value and application prospect.Monascus pigment is a natural edible pigment which is excreted by monascus in the metabolic process,compared with artificial color,security was obvious;at the same time compared with other natural edible pigment,its strong thermal stability and pH stability,strong protein dyeing property,various color hue,brilliantly colored,high color value,short production cycle.These several advantadges constitute the foundations of the special status of monascus pigment.Our country is the major producing manufacturer of monascus.The major manufacturers of monascus are distributed in Fujian,Zhejiang,Guangdong,Taiwan and so on.Fujian is the major producing area of traditional production,the output and export are in leading position at home,both exceed half of country's.Therefore, further study and exploitation of monascus pigment has significant importance.In this study, according to liquid culture and solid culture,extract monascus pigment by ultrasonic assisted extraction,discuss the relationship between extractions,bacterial strain,condition of culture,culture medium and the color value and pigment hue of monascus pigment.The results showed that:1) Discussed the relationship among extraction frequency,extraction temperature extraction power,extraction time and extract result. The obtained results indicated that the optimized technology parameters were as follows: extraction frequency 100KHz,extraction power 300W and extraction temperature at 60℃for 15 minutes. At this optimization scheme,extract result is similar to the extract result of national standards, the extraction time is truncated 75%.2) Determined the criteria of value hue by HPLC-DAD and spectrophotometry: E388/E505>1.23 is partial to yellow,E505/E388>1.24 is partial to red.3) Determined Monascus S as the best bacterial strain by culture and microscopic examinate.4) The three factors(rotational speed,volume of medium and pH) which affected the color value were optimized by L9(34) orthogonal test.The obtained results indicated that the optimized parameters were as follows:180r/min rotational speed, 50mL/bottol volume of medium,pH=5.5.5) Based on three factors quadratic general rotary design, to determine the color value (Y₁) and the pigment hue partial to yellow (Y₂),three factors including the concentration of ammonia sulfate (X₁) , the concentration of folic acid (X₂) and the concentration of Zn²⁺ (X₃) were chosen to study their effect on the color value and pigment hue of monascus pigment.The regression equations is as follows: Y₁=102.99217-5.53929X₁-2.76743X₂+8.42388X₃-3.65014X₁²-4.37935X₂²-9.70214X₃²+3.52313X₁X₃ Y₂=1.62008+0.21783X₁-0.13732X₂²-0.04592X₃² Based on three factors quadratic general rotary design, to determine the color value (Y₂) and the pigment hue partial to red (Y₂),three factors including the concentration of nicotinic acid (X₁) , the concentration of monosodium glutamate (X₂) and the concentration of Mn2+ (X₃) were chosen to study their effect on the color value and pigment hue of monascus pigment.The regression equations is as follows: Y₁=104.92882+0.55393X₂+2.37938X₃-1.20547X₃² Y₂=1.54732+0.06922X₂-0.07759X₂²6) Based on solid state fermentation, liquid inoculum could raise the end color value and truncate the fermentation time,the best fermentation time is 12d. It is obvious,liquid inoculum is superior to solid inoculum.7) The four factors(nitrogen source complex liquid a,metal-salt complex liquid a,vitamin complex liquid a and pH) which affected the color value and the pigment hue partial to yellow were optimized by L₁₆(4⁵) orthogonal test.The obtained results indicated that the optimized parameters were as follows:4mL nitrogen source complex liquid a,3mL metal-salt complex liquid a,4mL vitamin complex liquid a and pH=5.The four factors(nitrogen source complex liquid b,metal-salt complex liquid b,vitamin complex liquid b and pH) which affected the color value and the pigment hue partial to red were optimized by L₁₆(4⁵) orthogonal test.The obtained results indicated that the optimized parameters were as follows:4mL nitrogen source complex liquid b,4mL metal-salt complex liquid b,2mL vitamin complex liquid b and pH=7.