K Nn mK - Amecamex.org.mx
K Nn mK - Amecamex.org.mx
K Nn mK - Amecamex.org.mx
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FSB1-2004<br />
Food Sience and Food Biotechnology in Developing Countries<br />
MATERIALS AND METHODS<br />
Starch was extracted from three natural sources (corn, wheat and potato) and it´s<br />
physico-chemical properties were determinated and compared with three commercial<br />
samples of corn modified starch. The variables evaluated were moisture content, ash,<br />
and acid content using the AOAC methods (1994), damaged starch determination using<br />
the colorimetric method of equivalents units of Farrand (Williams, 1969) and starch<br />
water retention capacity (Yamazaki, 1953).<br />
RESULTS AND DISCUSSION<br />
Starch from three differents natural sources: corn, wheat and potato was obtained. After<br />
that it´s physical and chemical properties were evaluated. The moisture content was<br />
very low in the corn and wheat starches (1.78 and 3.69 % respectively) while in the<br />
potato starch was high (15.34 %), this was due mainly to extraction method because the<br />
potato starch sample was dried in a oven for 3 days while corn and wheat starch were<br />
dried for 4 days. The table 1 shows the Water Retention Capacity of the starch samples.<br />
Corn starch had a big WRC (129.60 percent) of it dry weigth this may probabily for a<br />
less moisture content and damage starch in comparision to other starch samples. Potato<br />
starch had the highest amount of damaged starch with 28.8 %. All corn, wheat and<br />
potato starches had a big amount of ash (0.3, 0.15 and 0.27 % respectively).<br />
Table 1. Chemical composition of starches in 3 diferents natural sources.<br />
Starch % Moisture % Solids % Ash % WRC Acid (g % FEU<br />
sample<br />
ac.lactic)<br />
Corn 1.78 98.21 0.30 129.60 2.21 5.19<br />
Potato 15.34 84.66 0.27 79.12 0.07 28.80<br />
Wheat 3.64 96.36 0.15 76.51 0.95 29.46<br />
The table 2 shown the chemical composition of three commercial corn modified starches<br />
which are used for meat processing. It was observed that these commercial starches<br />
had higher moisture than the starches obtaind in our lab. The acid and other content<br />
were lower in the comercial starches than the starches obtained in our lab. WRC<br />
increased in the order 97.22 in the B900, 120.76 in the B950 and 143.73 in the B990. In<br />
comercial starches WRC was different among samples; this may be due to the grade of<br />
structure modification. In conclusion, it was observed that corn starches with and<br />
without modifications were better than potato and wheat starches.<br />
Table 2. Chemical composition in corn modified starch presents in the market<br />
Starch % Moisture % Solids % Ash % WRC Acid (g FEU<br />
sample<br />
ac.lactic)<br />
B900 10.24 89.76 0.170 97.22 4.2 x10 -4<br />
23.77<br />
B950 11.06 88.94 0.055 120.76 3.3 x10 -4 B990 11.17 88.83 0.122 143.73 3.0 x10<br />
29.67<br />
-4 27.58