In the present study, processed soymilks prepared by various
manufacturing methods were examined for quality by physical and
chemical methods. Viscosity, pH, soluble solids, total solids, fat
and protein content were used as indicators of quality. The principal
factor investigated was the protein content as measured by the
dye-binding procedure.
The manufacturing variables studied were soaking and blending
times, size of beans, sprouting of the beans, drying temperatures
for powdered soymilk, and hull-on and hull-off beans. The laboratory
method giving optimum quality comprised, soaking the beans for
four hours at 20°C, blending with boiling water for eight minutes
and filtering hot. Large and medium sized beans, with the hulls
removed, gave the highest quality soymilks. Pilot plant procedures
were developed by scaling up the laboratory methods.
Heat treatments were applied to soymilks with no added sugar,
5% and 10% sucrose, 5% lactose and 5% glucose. Heat treatment
had little effect on the protein content of soymilks with no added sugar or with 5% and 10% added sucrose as measured by the dyebinding
method. Browning was observed in the lactose and glucose
added samples as a result of prolonged heating. The dye-binding
capacity of the protein in soymilk varied with the sugar level, the
type of carbohydrate and the length of the heating period. The most
noticeable change due to heat treatment was an increase in viscosity.
Soymilks were spray dried in a Anhydro Spray Dryer. Both
drying temperature and drying time had an effect on the quality of
the dried milk. The sample dried at the higher temperature was
brown in color and gave lower test values for all the quality factors
investigated.
The Kjeldahl method for protein was compared with the dyebinding
method and the results showed that the dye-binding method was
suitable for estimating the protein content in soymilk.
Varieties of soybeans investigated were Merit and Kanrich with
the Merit soymilks being of higher quality. / Graduation date: 1964
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/27004 |
| Date | 14 February 1964 |
| Creators | Wong, Millie Miu-yee |
| Contributors | Dietz, James H. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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