Research On The Micro-grinding And New Jam Processing Technology Of Whole Orange

China is a big country for citrus production,due to the relative concentration of maturity and difficulty of long-term storage,the loss of fresh fruit decay can mitigated only by processing into citrus products.The pomace residue after processing of citrus accounts for 40% to 50% of the fruit quality.The discarded pomace is rich in bioactive,but difficult to be used.The development of citrus whole fruit products can effectively realize the full utilization of citrus,retain the citrus nutrition to the utmost extent,and producing no peel residue waste,which is of great significance for the citrus processing industry and environmental protection.In this study,orange was used as raw material,and the whole orange fruit was finely pulverized by high-pressure homogenization.The most suitable whole fruit pulp was selected for further processed into a jam product through rheological and other related knowledge,and the quality analysis of the jam was obtained.The main results are as follows:(1)The whole orange was micro-pulverized,and the grain size,total sugar,pectin,total phenol and total flavonoids content and rheological properties of the whole orange was analyzed after high pressure homogenization for 1~5 times when the pressure is 50 MPa.It was concluded that high pressure homogenization can effectively reduce the grain size of the whole orange pulp.After three times of homogenization,there was no significant difference in grain size reduction.After high pressure homogenization treatment,the contents of total sugar,pectin,total phenol and total flavonoids were increased significantly.High pressure homogenization could effectively improve the rheological properties of the whole orange fruit puree system.After three times of homogenizati--on,the orange pulp with high viscosity,good gel stability and certain fluidity was obtained.After three times of homogenization treatment,the orange pulp with small particle size,high viscosity,good gelation and stable system was most suitable for further processing into jam products.(2)Sensory score was used as the index,single factor and response surface test were used to optimize the process of the whole orange fruit jam.The results showed that when the addition amount of sugar was 35%,the microwave heating time was 260 s,and the microwave heating power was 770 W,the new whole orange fruit jam hadthe best formula and the highest sensory score.According to the optimal formula,the jam is bright yellow,uniform,coherent,taste comfortable,moderately sweet and sour,and has a rich orange aroma.(3)The quality of the new whole orange fruit jam was analyzed,and compared with three commercially available citrus jams,the results showed that the total sugar content and sluble solid content of the new whole orange jam were 43.60% and48.00 %,respectively,belonging to low-sugar jam;After microbiological testing,the total number of colonies,mold,yeast and the number of E.coli of whole orange jam are lower than national standards,and no salmonella or staphylococcus aureus were detected;high temperature concentration will significantly reduce total phenol and flavonoids in jam,but can effectively improve the rheological properties of the jam;Compared with commercial jam,the new whole orange jam has a moderate chewing viscosity,no browning,acceptable sensory evaluation and better than commercial citrus jam.