Study On The Drying Method Of Carrot Pomace And The Extracting Technology Of Carotenoids

Carotenoids, a kind of functional pigment, was focused on and widely used in the field of food, pharmaceuticals, feeding stuff, and cosmetic. In terms of integrated exploitation and utilization for carrot, the drying method of carrot pomace and the extracting technology of carotenoids in the pomace were studied. 1) The drying method of carrot pomace. This research focused on the dynamic curve of the water and carotenoids content in the pomace during the drying progress, comparing the effect of hot-air drying, vacuum drying, and combined drying techniques. The result showed that the optimal was combined drying technique: first drying the carrot pomace in 85℃hot-air for 45 minutes, and then vacuum 75℃drying. When the water content was 8%, the time taken was 135 minutes, and the lose rate of carotenoids was 2.1%. 2) The extraction of carotenoids. Dry carrot pomace was taken as experimental material. Organic solvent and supercritical CO₂ fluid were used to extract the carotenoids in it , and the two extracting techniques were compared. For solvent carotenoids extraction, the main affecting factors, such as solvent, grinding granularity, liquid-solid ratio, extracting times, temperature, and distilling time, were studied. Based on the single factor experiment, the three-factor quadric universal rotational combination design was adopted to study the effects of temperature, liquid-solid ratio and grinding granularity on carotenoids extraction rate. The result showed that the optimize technology for carotenoids extraction from carrot pomace was: ethyl acetate/ethanol (2:1,v/v) as solvent , 0.08mm grinding granularity, 57℃temperature, 15:1 liquid-solid ratio, and 2 times extraction with 60min per time. Supercritical CO₂ fluid extraction is a kind of new extracting technology. Based on the fundamental principle of the technology, extracting pressure, extracting temperature, extracting time, grinding granularity and CO₂ flow rate were studied. The four-factor quadric universal rotational combination design was adopted to study the effect of grinding granularity , temperature , pressure and time on the carotenoids extraction with super-critical CO₂. The technology for carotenoids extraction from carrot pomace was optimized. The best extracting technology was: temperature was 60℃, pressure 50Mpa, grinding granularity 110 orifices, time 130 min, and CO2 flow rate 1ml/min.