| 摘要 |
Prolonged shelf life non perishable cottage cheese of lumpy consistency is prepd. as a base for various prods. contg. it. Good quality fresh milk is sepd. into skimmed milk and cream fractions. Both are pasteurised and cooled. Pasteurisation parameters are so chosen, that the N index of denatured whey proteins should be in the region of 3-5 mg N/g fat free dry milk solids. Cream is homogenised and mixed with the prepd. skimmed milk to a required fat content. This mixt. is allowed to set following the addn. of mesophilic lactic acid bacteria. A mixture starting culture ensures, that desired flavour and acidity should be reached, and that the culture should produce 100-200 mg/l di:acetyl-acetoin and 10-100 mg/l CO2. Resulting polysaccharides should lead to a ''glutinous'' consistency at increased viscosity and water retention levels. A preferred bacterial starting culture contains a mixt. of following gps. registered in the collection of the Hungarian Milk Industry Research Institute (MTKI) under iode MTKI-311. I.e. lactococcus lactis subsp. cremoris; Lactococcus lactis Sb. Usp. lactis; Leucoonostoc mesenteroides subs. cremoris; Leuconostoc pseudomesenteroides and lactococcus lactis subsp. lactic biovar diacetylacis. The clotted prod. is cut into pieces, synerised, and the whey and clotted mixt is heated to 40-45 deg C temp. Appr. 30% of the whey is drained off. The remaining mixt. is heated further to 65 deg C temp. at its natural pH of 4.5-4.7, under anaerobic conditions, at a minimum heating rate of 0.5 deg C/min. Excess whey is drawn off leaving sufficient to just cover the clods. Some of the pasteurised and cooled whey is poured back onto the mixt. to cool it to 40-45 deg C at a minimum rate of 5 deg C/min. Most of the whey is trickled off and treated cottage cheese is poured under anaerobic conditions into moulds and these are cooled to 5 deg C temp. at a minimum rate of 0.1 deg C/min. Slabs formed are packaged into a composite, synthetic, foil assembly and by maintaining a residual pressure of 0.15 bars, or at a pressure reduced to 0.15 bars, or at 0.6 bars, max. by increasing the 0.15 bar pressure using CO2. The composite synthetic foil comprises an O2 permeable foil having a permeability of 2 cu.cm/sq.m-d-bar and a CO2 permeable foil having a permeability of 60 cu.cm/sq.m-d-bar. Permeabilities are measured at 23 deg C temp. and 0 rel. humidity. The method of prepn. is suitable for large scale manufacture, it is highly palatable, has prolonged shelf life when cooled, does not ooze whey out and compares very favourably with conventional cottage cheese prods. |
