The effect of heat treatment on the chemical composition of canned meat.

Abstract

Beef, pork and chicken meat were used in this study. Heat treatments were carried out at 115 ºC in stationary and rotating autoclaves, 125 ºC in stationary and rotating autoclaves, 125 ºC in stationary and 125 ºC but higher Fo value in stationary and rotating autoclaves.



The results of the analysis showed higher protein values in the range of 20.54% to 23.92% (autoclaved) and 20.25% to 20.85% (raw) beef; those of pork samples were from 19.12% to 21.68% (autoclaved), 19.19% to 19.83% (raw) while chicken samples were from 22.00% to 24.76% (autoclaved) and raw sample is 20.75% respectively. In the case of fat content, autoclaved beef samples showed higher values than the raw samples in the range of 3.0% to 4.5% (autoclaved), 1.0% to 1.5% (raw), while the reverse was the case with pork and chicken where the range for pork was from 2.5% to 5.0% (autoclaved), 5.0% to 5.5% (raw), and chicken from 0.5% to 2.0% (autoclaved) and 2.5% (raw) samples respectively. The ash content of autoclaved beef and pork samples showed lower values than their raw samples and were in the range of 1.13% to 1.53% (autoclaved) and 1.01% to 1.74% (raw) for beef and 1.20% to 1.62% (autoclaved), 1.14% to 1.68% for raw pork samples while autoclaved chicken samples showed higher values than the raw sample in the range of 1.20% to 1.62% (autoclaved) and 1.02% raw samples respectively. Apart from two autoclaved pork samples SA3 (stationary) and SF5 (rotating) that showed higher moisture content than their raw samples other pork samples (SAI, BF2, SA4) beef and chicken samples showed lower values. The moisture content of pork sample (SA3) was 76.5% (autoclaved) 72.0% (raw) SF5 samples was 75.0% (autoclaved) and 73.0% (raw) respectively.



Amino acid content of the sample also showed that by far a higher effect exists with the behaviour of individual amino acid of the raw material than the parameters of heat treatment. In all product samples cystein and tryptophan contents of autoclaved samples were lower than those of the raw samples.



The amino acid range for beef was from 99.24 g to 99.98 g (autoclaved). 100.00 g to 103.90 g (raw); pork samples 102.24 g (raw); chicken samples 99.99 g to 100.01 g (autoclaved) and 100.01 g for raw samples respectively. Thiamine retention was higher in canned beef than other canned meat. More thiamine was retained in autoclaved pork in rotation than in autoclaved stationary treatment. Thiamine in beef ranged from 0.85 g to 1.20 mg (autoclaved), 1.86 mg to 2.50 mg (raw samples); pork 0.44 mg to 0.81 mg (autoclaved) and 1.19 mg to 1.80 mg (raw); chicken 0.06 mg to 0.10 mg (autoclaved) and 1.25 mg for raw sample respectively. The result on thiamine retention showed that, that of canned chicken was more sensitive to heat treatment than other canned meat samples.



On the whole, the results of this study showed that products heating largely by conduction-stationary heat treatment resulted in acceptable quality meat products.

Global Journal of Pure and Applied Sciences Volume , No 1 January (2001) pp. 49-56



KEY WORDS:

Heat treatment, canned meat, chemical composition, thiamine retention.