Optimization of Technology of Elaeagnus angustifolia and Hippophae rhamnoides Compound Jam by Response Surface Methodology and Prediction of Storage Period

Using Xinjiang Kashi Elaeagnus angustifolia as raw material, adding Xinjiang Jinghe Hippophae rhamnoides instead of citric acid as sour agent, compound jam was developed. The adding amount of seabuckthorn and white sugar, boiling time were studied by single factor experiment. According to total soluble solids（TSS）content and sensory scores, the formula of Elaeagnus angustifolia and Hippophae rhamnoides compound jam was optimized by Box-Benhnken central composite design. The shelf life was predicted by establishing Q10model. The results showed that the formula of the compound jam of Elaeagnus angustifolia and Hippophae rhamnoides was as follows: the set dosage of Elaeagnus angustifolia 100%, the addition of Hippophae rhamnoides 12%, white sugar15%, and boiling time 25 minutes. The compound jam with relatively good quality was prepared, with yellowish brown color, moderate sweet and sour taste and good texture, in which soluble solids content was 66%, pH 3.80,protein 0.57%, polyphenols 4.32 mg/g, flavonoids 0.67 mg/g, and reducing sugar 3.67%. Microbiological indicators met national standards. The established Q10model predicted the shelf life of the product was 177 days at 20 ℃.