Physalis Persistent Calyx Polysaccharide Powders Process And Its Characteristics Research

Physalis alkekengi L. var. francheti, commonly known as "the red girl", belongs to perennial herb. Alkekengi can produce a kind of spherical berry fruits, of which the sarcocarp is rich in amino acid, protein, cellulose, fat and other nutrients while being tasty with sweet and sour flavor. The persistent calyx of Alkekengi can be used as a medicine which tastes bitter and has the efficacy of relieving cough, easing pain and clearing heat from throat when soaked in water to drink. Polysaccharides is one of the major functional ingredient of the persistent calyx. However, polysaccharides in the persistent calyx has not been put into better use as it should be in production. In this context, on the basis of the ingredients analysis on the persistent calyx of Alkekengi, the paper is mainly focused on the extraction technology and purification technology of polysaccharides in the persistent calyx and some characteristics research on polysaccharides in persistent calyx, such as the physicochemical property, processing adaptability, rheological property, antioxidant activity, ect. so as to develop a compound beverage with the efficacy of clearing lung heat to relieve cough and clearing heat from throat when taking polysaccharides in the persistent calyx as one of its addtional agents.With the polysaccharides yield in the persistent calyx being the index, the research has optimized the extraction technology by Response Surface Method based on the single-factor experiment, thus get the optimum conditions of hot water extraction for polysaccharides in the persistent calyx as follow:extraction temperature95℃, solid-liquid ratio1:25, extraction time4hours, polysaccharide yield3.81%.The color removing test showed that the best decoloration resin is decolorization No.l, the best sample volume is2BV, the flow velocity is1.5mL/min, and the column temperature is the room temperature without adjusting of the pH. The research adopts calcium chloride method for deproteinization after comparing the effect of isoelectric point method, calcium chloride method and sodium chloride method.Characteristic analysis on purified polysaccharides in persistent calyx indicates that: polysaccharides in persistent calyx has good solubility, the DSI value (dry matter solubility index) is97.7%, the calyx polysaccharide solution has thixotropy while the apparent viscosity increases with its concentration and decreases with the rise of temperature; persistent calyx polysaccharide shows strong oil absorbency and certain level of hygroscopicity, moisture retention and foamability with good foam durability, which means it can be used in food processing; the persistent calyx polysaccharide powder has small bulk density and is loose in structure; the results of DSC shows that changes may have been taken place to the persistent calyx polysaccharide during the increasing of temperature, for there are two melting peaks of the DSC curve; ultraviolet spectrum analysis indicates that the calyx polysaccharide may has a small quantity of nucleic acid and protein while infrared spectrum analysis indicates that the calyx polysaccharide shows the characteristic absorption peak of mannose and D-Grape pyranose. Vitro antioxidant experiment results show that the calyx polysaccharide shows certain fuction of scavenging free radicals and has potential antioxidant capacity.Based on the study of persistent calyx polysaccharide characteristics and the composite beverage technology, with sensory score as the evaluation index, the paper identifies the optimum formula of alkekengi and siraitia grosvenorii compound beverage which contains persistent calyx polysaccharide:ratio of juice1:4(alkekengi to siraitia grosvenorii), the original compound juice25%, sugar6%, Citric acid0.1%, persistent calyx polysaccharide5mg/mL. With suspension stability and centrifugal sedimentation rate being indexes and orthogonal experiments to get the results optimized, the research identifies that the final composite stabilizer dosage should be:0.1%of CMC,0.1%of xanthan gum and0.1%of pectin.The final sterilization conditions:boiling water sterilization for15min.