The composition and some qualitative aspects of ground beef
offered for sale in Corvallis, Oregon were studied. Samples were
purchased from six retail markets twice weekly throughout a six
week test period. Three stores were independently owned and operated
and three were chain stores.
Differences in moisture, fat and protein levels of ground beef
samples among the six stores and between chain and independently
owned stores were statistically significant. Differences in composition
between sampling days (Tuesday versus Friday) and between
replicate weeks were generally not significant. Ground beef from
chain stores was generally characterized by higher moisture and
protein levels and lower fat levels. Thirty-two percent of all samples
(50 percent of the independent stores and 14 percent of the chain
stores) exceeded the legal limit of 30 percent fat.
Moisture:protein ratios ranged from 2.53 to 4.24 while the
average value was 3.59. About 28 percent of all samples had ratios
in excess of 3.70. Differences in moisture:protein ratios between
chain and independent stores were not significant.
Although differences in extract-release volume (ERV) of ground
beef obtained from the various stores were significant, differences
between sampling days, replicate weeks and chain versus independent
stores were not. Resazurin reduction times of ground beef among
individual stores, between sampling days, replicate weeks and chain
versus independent stores were not significantly different. The
correlation between ERV and resazurin reduction time was low
(r = 0.21) suggesting a poor relationship between these two procedures
for assessing microbial contamination in ground beef.
Differences in nonprotein nitrogen (NPN) levels of samples
among stores and between sampling days were statistically significant.
Only minor differences in NPN levels between store types and
replicate weeks were observed. Soluble protein levels appeared to be
a reflection of total protein.
Iodine numbers of ground beef fat ranged from 43.7 to 53.6 and
were significantly higher in ground beef purchased from chain stores.
Price per pound of ground beef and price per pound of protein
were significantly different among the six stores. The price per
pound of meat was significantly higher in the chain stores than in the independent stores. However, price per pound of protein and price
per pound of soluble protein were essentially the same for the two
types of stores.
Recommendations for quality control of ground beef sold at the
retail level are discussed. / Graduation date: 1968
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/26799 |
| Date | 28 November 1967 |
| Creators | Lee, David Bing-en |
| Contributors | Anglemier, Allen F. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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