A, raw material formula and quality requirements
White sugar: 14%, clean and dry white crystal, purity not less than 99%; Skim milk powder: 8%, fat content below 1.0%, skim milk solids 94.8%; Apple jam: 6%, fineness 6-8 microns, fresh; Delicate taste and rich apple flavor; Pectin: 0.3%; Corn starch: 5%; Margarine: 4%; Citric acid: 0.04%; Malate: 0.1%; Ethyl maltol:/10 ppm；; Appropriate amount of apple and cream essence; The rest is water.
Second, the main points of operation
① Preparation of applesauce. First-class high-quality apples are selected for pretreatment, then crushed by a crusher, and then superfine crushed by a colloid mill, so that the taste is delicate and the fineness is required to be 6-8 microns; Filtering, sterilizing and cooling to obtain applesauce.
(2) Mixing and modulation of raw materials. According to the formula, white sugar, margarine, pectin, corn starch, applesauce, emulsifier and proper amount of water are weighed. Pectin should be mixed with sugar ten times its own weight before feeding, so as to avoid adhesion between pectin particles and affect the melting speed. Put the above raw materials into a batching pot and stir evenly.
3 Adjust the acidity. Citric acid and malic acid are mixed with appropriate amount of water according to the formula to make acid adjustment solution. When the acid is adjusted for the first time, the PH value of the feed solution is controlled between 3.4 and 3.8. At this time, too high or too low acidity will lead to the instability of protein in the feed liquid, which is very important for the stability of the feed liquid. After the first acid adjustment, skim milk is added to the feed solution to raise the PH value of the feed solution to 4.2-4.3. At this time, the second acid adjustment is carried out to adjust the PH value of the feed solution to 3.6-3.8.
4 sterilization. The temperature is controlled at 70-80 DEG C for 30 minutes.
⑤ Homogenization. The pressure is controlled at 15- 17 MPa and the temperature is controlled at 60-70℃. Homogenization is the key link in ice cream production. Because the fat content of this product is only 4%, it contains a lot of raw materials such as coarse applesauce. If the homogeneity is not good, the fat will float to form obvious Xue Huadian, and then the jam will sink to form jam aggregation points, and the product will be rough.
⑥ Cooling aging. The homogenized feed liquid is immediately cooled to 2-4℃. Aging at 2-4 DEG C for 2-3 hours.
⑦ Frozen. The aged ice cream is frozen at -2-4℃, and essence and ethyl maltol are added at this time. Through the continuous stirring of the freezing mixer, the various components in the mixed liquid are further mixed evenly.
(8) Filling and packaging. Frozen ice cream is filled and packaged according to different specifications.
Pet-name ruby hardening, inspection, finished products. The filled and packaged ice cream is quickly put into the cold storage at -30℃-40℃ for 6-7 hours, and it is the finished product after inspection and stored at-18℃.
Third, quality standards ① sensory indicators. Color: Bright flavor: It has a strong apple flavor, moderate sweet and sour, cool and thirst-quenching, and stimulates appetite. ② Physical and chemical indexes. Meet the national standards. ③ Microbial indicators. Total number of bacteria: ≤ 15000 /ml, number of Escherichia coli: ≤450/100 ml, pathogenic bacteria: undetectable.