The Study On Nutritional Properties And Storage Stability Of Carrot Beverage Fermented By Probiotics

Carrot beverage fermented by probiotics was subjected for study. Its nutritional properties and storage stability were explored. In order to understand nutritional characteristics and physicochemical property of the carrot beverage fermented by probiotics, its nutrients and physicochemical properties were determined. The polysaccharide was extracted to reveal characteristics of polysaccharide from the carrot juice fermented by probiotics. In addition, the beverage was stored in the condition of 4, 25, 37? for 120 d and regularly measured on their physicochemical properties and the characteristics of polysaccharide, to reveale the stability of carrot beverage fermented by probiotics. The conclusions are as follows:(1)The contents of protein, fat, amino acids, trace elements and other nutrients from carrot beverage fermented by probiotics were determined. Protein and fat content were both 0.2%. Sixteen kinds of amino acid was in a amount of 8.836 mmol/kg. Although the content of Ca, K, Na element was prominent, elements such as zinc, Fe, Cu, Mn and Se were low in content. Entrifugal sedimentation rate of the beverage was 10.88%, and the soluble solids content was 10.3 Brix. Acidity value, particle size and potential value were 2.09g/kg, 662.47 nm and-15.35 m V, successively. Viscosity of the beverage decreased with the shear rate, and was assumed to be pseudoplastic fluid.(2)The polysaccharide was extracted by two different ways including hot water extraction or centrifugate extraction. The obtained fractions were named as water extracted polysaccharide(WEP) and centrifugate extracted polysaccharide(CEP), respectively. Structural characteristics differences between WEP and CEP among neutral sugar content, protein content, uronic acid content, relative molecular weight, infrared spectrum and morphology appearance were highlighted. The results showed that basic physical-chemical properties between the two fractions were similar. However, the differences of neutral sugar and protein contents between WEP and CEP were significant. HPGPC showed that the relative molecular weight of WEP and CEP were 30000 and its distribution of WEP and CEP were similar to each other. The typical polysaccharide absorption peak was both found in IR spectra of WEP and CEP. Scanning electron microscopy showed that the WEP and CEP was lamellar with smooth surface. In conclusion, there was little difference in the structural characteristics between the water soluble polysaccharide produced by water extraction and centrifugation directly.(3)The storage stability of carrot beverage fermented by probiotics under the conditon of 4?, 25?and 37? was characterized. By determining changes of particle size, Zeta potential, viscosity, color value, acid value, soluble solids, centrifugal sedimentation rate changes, beverages stability was confirmed to be good in the above storage temperature. The results showed that particle size fluctuated from 640 to 680 nm. Zeta potential fell from 19.26 from 20.35 m V. Red and yellow index increased 0.16%, 0.17%, respectively. Acid value increased from 1.94 to 2.05 g/kg, Soluble solids keeped at 10.5 ~ 10.7 Brix. The centrifugal sedimentation rate also increased only 0.04%. Rheological properties of carrot beverage fermented by probiotics showed a typical pseudoplastic fluid.(4)The impacts of storage time and storage temperature on water-soluble polysaccharide from carrot beverage fermented by probiotics were analyzed. The water-souble polysaccharide from carrot beverage fermented by probiotics storaged under 4?25?37? temperature for 0?5?10?30?60?90?120 d was directly extracted by centrifugate extraction. Physicochemical properties among neutral sugar content, protein content, uronic acid content, relative molecular weight, monosaccharide composition, particle size, Zeta potential and morphology appearance were determined. The particle size of CEP4, CEP25, CEP37 polysaccharide were in 110 ~ 130 nm range and were negatively charged. But there were some differences in neutral sugar content, protein content, uronic acid content. There were two kinds of components(Peak1, Peak2) in each polysaccharide measured by a multi-angle laser light scattering chromatography. Heavy molecular weight range of each component was 900 ~ 1000 KDa, 60 ~ 70 KDa, the polysaccharide was mainly composed of Ara, Gal and Gal A. Scanning electron microscopy showed that the water soluble polysaccharide was lamellar and mitoplast. In conclusion, the physicochemical properties and structure characteristics of the water-soluble polysaccharide were less affected by the storage time and storage temperature.The researches showed that carrot beverage fermented by probiotics was nutrious. Various physicochemical indexes of beverage stored at different temperature for 120 d were stable. Polysaccharide structure and physicochemical characteristics were not shown to be significant difference. Therefore, stability of the beverage fermented by probiotics was good.