Forming Technology And Ripening Acceleration Of Ultra-Hard Cheese

To facilitate the research of the process and ripening acceleration of hard cheese, cheese sample was processed following the processing technology of Parmesan cheese. The investigation was conducted via single factor and orthogonal experiments. The effects of different factors in the cheese processing on moisture contents of ultra-hard cheese were studied. The protease was added in the cheese to accelerate cheese ripening. The principal results and conclusions were as follows:The optimum processing conditions of ultra-hard cheese are as follows:the terminated pH6.4, rennet0.004%, CaCl20.015%, the scalding time40-50min, the scalding temperature53-55℃, the final pH of drain the whey6.0, then the sample moisture was32%-35%.The optimum processing conditions and procedure for the addition of protease of ultra-hard cheese are as follows:The final pH of drained whey is5.7-5.8, the temperature8℃, the RH60%, time24h, and the moisture of the sample could be25.2%, after this, the sample is crushed into granules,1%protease and3%salt are added for the sample granules and the vacuum-packed product is ripened in a thermostatic chamber at the temperature of15-17℃.The physicochemical characteristics of ultra-hard cheese during ripening are accessed that the pH in the cheese decreased during the primary ripening and then increased, the lactic acid concentration in the cheese increased during the primary ripening and then decreased slightly.The peptides of the water-soluble N fractions were analyzed by reversed-phase HPLC. The ratio of hydrophobic to hydrophilic peptides decreased and the content of total FAA as well as peptides significantly increased as the protease was added.Headspace solid phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to analyze the volatiles in the samples. The alcohols, ketonesand esters remarkbly increased and hydrocarbons, volatile organic acids decreased as the protease was added. Aldehydes, FFA and the other volatiles appeared no significant changes.The texture of sample was analyzed by Texture analyzer (TPA). The springiness, gumminess, cohesiveness, chewiness and adhesiveness decreased and hardness increased with the moisture of the cheese decreased.The FAA in the cheese were analyzed that three FAA occurred more than origenal as the protease was added. The content of each FAA increased respectively.