Determination of maturity value of fully cooked pork loin in cuisine

Abstract: The term maturity value (M) can be physically defined as the equivalent heating time (min) that is required for when culinary quality reaches a degree of being cooked properly at a specific reference temperature. The M value is a dynamic function which describes the change of the food quality being fully cooked and characterizes the degree of being fully cooked in cuisine. The termination maturity value (MT) is the M value reached at the time of being fully cooked. "Huohou" can be dynamically defined as the culinary operation minimizing the over-heated value when culinary quality reaches being fully cooked. Theoretic analysis and numerical simulation were studied in previous literature; however, whether the MT value exists or not, or whether its value is steady and merely relates to dynamic parameters and thermal history, has not been verified by experiments until now. As a result, it was necessary to measure MT value and its z value and analyze the influence factors under designed experimental conditions. A method to measure the MT value was established for the selected samples--pork loin. As the judgment of being fully cooked is subjective, sensory evaluation was used in cuisine. Firstly, samples with specific M values determined by the system of data acquisition and analysis on heat transfer and kinetics were prepared under different experimental conditions, i.e. size, shape, initial temperature, temperature and type of heating medium. In addition, a selection method of sensory evaluation difference tests was used to confirm the degree of being fully cooked in samples according to color, odor and texture, respectively. Under these conditions, the corresponding MT of color, odor and texture were regarded as the average M of being fully cooked samples. Based on the color, odor and texture weight given by experts, an integrated MT was acquired by the weighted average. Finally, a set of MT was obtained in the light of a different z value under the same experimental conditions. A corresponding z was the reasonable zM of cuisine being fully cooked when this set of MT standard deviation was minimum. The results indicated that an average IMT of A and B of pork loin were 0.51 and 0.31 min respectively, and MT values were proven to be invariable under different sizes, shapes, initial temperatures, temperatures and type of heating mediums, and could only be determined only by different pork loins. Since the zM value of M represents the sensitive degree of being fully cooked to heating; the lower the zM value, the easier being fully cooked is to be reached. The zM of meat cuisine M value was close to 10℃, which was inferred, approximately, from experimental results and the z value range of protein denaturation. For the same sourced pork lion, center points had different thermal histories and being fully cooked time had the same cooked quality when samples reached the same center MT. The above experimental result has provided evidence for the M value theory. M value is merely related to thermal history and zM; therefore, it can be widely used in cuisines especially suitable for the engineered calculated process of food being fully cooked. The above-mentioned results conformed to the definition of the MT value and the relevant parameters scope. To prove the M value theory thoroughly, much more in-depth and widespread experiments will be required.