Cooking temperature indicator

Solvent Process. In the solvent process, or solvent cook, water formed from the reaction is removed from the reactor as an a2eotropic mixture with an added solvent, typically xylene. Usually between 3 to 10 wt % of the solvent, based on the total charge, is added at the beginning of the esterification step. The mixed vapor passes through a condenser. The condensed water and solvent have low solubiUty in each other and phase separation is allowed to occur in an automatic decanter. The water is removed, usually to a measuring vessel. The amount of water collected can be monitored as one of the indicators of the extent of the reaction. The solvent is continuously returned to the reactor to be recycled. Typical equipment for this process is shown in Figure 2. The reactor temperature is modulated by the amount and type of refluxing solvent. Typical conditions are ... 

Campbell (6) was perhaps the first to investigate the relationship between tenderometer values for raw peas and the texture characteristics of collateral samples after freezing and cooking. A high degree of correlation was observed. The investigations of Nielsen and co-workers (31) indicate the usefulness of the instrument for estimation of maturity in peas intended for freezing preservation. In order to secure consistent and reproducible results, the instrument requires standardization and calibration, and the measurements must be made under standardized conditions of temperature and interval after harvest. 

N-Nitrosamine inhibitors Ascorbic acid and its derivatives, andDC-tocopherol have been widely studied as inhibitors of the N-nitrosation reactions in bacon (33,48-51). The effect of sodium ascorbate on NPYR formation is variable, complete inhibition is not achieved, and although results indicate lower levels of NPYR in ascorbate-containing bacon, there are examples of increases (52). Recently, it has been concluded (29) that the essential but probably not the only requirement for a potential anti-N-nitrosamine agent in bacon are its (a) ability to trap NO radicals, (b) lipophilicity, (c) non-steam volatility and (d) heat stability up to 174 C (maximum frying temperature). These appear important requirements since the precursors of NPYR have been associated with bacon adipose tissue (15). Consequently, ascorbyl paImitate has been found to be more effective than sodium ascorbate in reducing N-nitrosamine formation (33), while long chain acetals of ascorbic acid, when used at the 500 and lOOO mg/kg levels have been reported to be capable of reducing the formation of N-nitrosamines in the cooked-out fat by 92 and 97%, respectively (49). 

Cook and co-workers suggested that partial racemization had occurred in the acid/base mediated isolation of (-)-tetrahydroroeharmine (41), Fig. (10) [35]. Proof was obtained by treating 41 with TFA/CH2CI2 at room temperature, which resulted in racemization of 41. In an experiment with TFA-rf, deuterium was incorporated only at C-5 and C-8, not at the epimeric centre, indicating that a mechanism analogous to Mechanism 1 was not active. Reddy and Cook, in contrast, proposed that the mechanism depicted in Scheme (10) was responsible for the racemization of (-)-tetrahydroroeharmine (41). This mechanism is analogous to Mechanism 3. Interestingly, compounds with more than one asymmetric... 

Sample Preparation. Broiled beefsteaks were selected as the basic experimental material. Steaks 5/8 inch thick and 3 inches in diameter were prepared from major round muscles of choice grade beef and were oven-broiled 3 inches from the heating elements for 12 minutes on the first side and 10 minutes on the second. These conditions produced an internal temperature of about 75°C., which was sufficient for complete enzyme inactivation (8). This cooking schedule produced a medium well done steak. Either all steaks to be used in a given test series were prepared from the same carcass or steaks prepared from different carcasses were randomized with respect to treatment variables. All samples were prepared this way unless otherwise indicated. 

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