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An Integrated Approach to Improve the Quality and Safety of Selected Foods

Investigators
McWatters , Kay
Institutions
University of Georgia
Start date
2000
End date
2005
Objective
  1. Collaborate with food microbiologists to determine optimal antibacterial treatments and process/handling conditions which maintain sensory quality of selected fruits and vegetables.
  2. Obtain qualitative information from consumers to guide the development of processes to inactivate foodborne pathogens on fruits and vegetables and in developing product applications utilizing legumes, oilseeds, and cereals.
  3. Characterize basic functional properties of ingredients from legumes, oilseeds, and cereals and determine their performance and acceptance in appropriate food product applications.
  4. Relate objective quality measurements of ingredients and finished foods to sensory attributes and product acceptability.
More information
APPROACH: Treatments utilizing mixtures of lactic acid and hydrogen peroxide applied at various times and temperatures will be studied for their effectiveness in killing Escherichia coli O157:H7, Salmonella spp., and Listeria monocytogenes on apples, oranges, and iceberg lettuce. The effectiveness of ozonated water for reducing/inactivating Listeria monocytogenes on alfalfa seeds and sprouts will be determined. Sensory evaluation will be conducted on fruits and vegetables subjected to the most promising treatments immediately after treatment and after 2, 6, and 10 days of refrigerated storage. Qualitative information about consumers' general knowledge of food safety; their current handling, storing, and food preparation practices; and their purchase and consumption habits will be obtained via focus groups, interviews, and questionnaires. This information will be related to consumers' demographic characteristics and acceptability ratings. Basic functional properties (solubility, emulsification, foaming, water absorption, gelatinization, and viscosity) of flours, processed from selected legumes (e.g., cowpeas), oilseeds (e.g., peanuts) and cereals (e.g., wheat) will be determined. Results derived from functionality measurements will be used to select potential food products in which to evaluate the performance of the legume-oilseed-cereal flours as ingredients. Examples of potential product applications are snack chips, cookies, sauces, and yeast-raised bread. Quality measurements (color, texture, composition, volume, spread characteristics), consumer acceptance, and willingness-to-buy finished products will be determined. Relationships between functional and objective quality measurements to consumer ratings of quality will be made. Involvement of the consumer initially and during the development process is expected to increase the probability of success and acceptance of technologies and products.

PROGRESS: 2000/07 TO 2005/06
Previous work conducted on development of a baked peanut chip showed that this snack food could be processed from partially defatted peanut flour milled from cold pressed peanuts. However, because of the composition of the peanut flour (40-44% protein, 10-14% fat) and high level of usage (greater than 50% of total ingredients in some formulations), some of the baked products were undesirably hard and tended to pack in the teeth when chewed. Sensory evaluation tests showed potentially high consumer acceptance of this healthy snack food, particularly if the texture could be made softer and more cracker-like. Commercial light roast peanut flour (50% protein, 12% fat) was used in a basic cracker formula at levels ranging from 7 to 42%, with and without rice flour. Ten flour mixtures based on a three-component (wheat, rice, peanut) constrained simplex lattice design were investigated. Process conditions (mixing, sheeting, cutting and baking) were established in preliminary trials. All 10 formulas had instrumental color and texture measurements that fell within the range of values determined for five commercial crackers (Saltines, Munchems, Wheatables, Wheatsworth, Wheat Thins). All test crackers contained more nitrogen (1.74 to 3.87%) and thus more protein than the commercial crackers (1.24 to 1.68% nitrogen). Not surprisingly, formulas #3 and #10 which contained the highest levels of peanut flour (42 and 30.33%, respectively) had the highest nitrogen content (3.87 and 3.15%, respectively). The flour mixture with the highest level of peanut flour that also exhibited the best overall dough handling characteristics (formula #6) contained 58% wheat, 17.5% rice and 24.5% peanut. This mixture was used as a control for further development to incorporate seasonings that could enhance the flavor of the basic cracker. The flavor variations were: garlic powder, 2%; Cajun salt, 2.4%; cheddar cheese, 10.5% and cheddar cheese/cayenne, 10.4%. All variations and the control were formulated to contain ~1% salt. Consumers (n=75) evaluated the sensory quality of the crackers. Crackers made with cheddar cheese or cheddar cheese/cayenne pepper received the highest hedonic ratings for appearance (7.0 = like moderately), color (7.1-7.2), aroma (6.3-6.5 = like slightly), flavor (6.4-6.5), texture (6.6-6.7) and overall liking (6.4-6.7). Consumers (67%) were concerned about the nutritional quality of the crackers they consumed and 71% were willing to pay more for crackers with enhanced nutritional quality. The increase in obesity and its associated health risks for consumers (increased levels of low-density lipoprotein and total serum lipids) strongly suggested the need to modify the initial formula to use a shortening with no or low-trans fatty acid content. Five low-trans shortenings were investigated and compared to regular Crisco for dough handling properties and finished product quality. Low-trans Crisco had similar appearance, dough handling, and baking performance compared to regular Crisco. Therefore, processing of a peanut flour chip or cracker that is acceptable to consumers is feasible and has potential for expanding the use of peanuts.

IMPACT: 2000/07 TO 2005/06
Involvement of targeted consumers early in the process of developing new antibacterial treatments for fresh fruits and vegetables and new products from peanuts will increase the probability of success of the process/product. Because the total time (20 min) involved in application of the antibacterial and neutralization treatment, adoption of the technology may be more appropriate for processing plants or packinghouses than for the home. Reduced fat products and new applications for peanuts will benefit consumers and producers.

Funding Source
Nat'l. Inst. of Food and Agriculture
Project source
View this project
Project number
GEO01620
Accession number
0185498
Categories
Escherichia coli
Listeria
Bacterial Pathogens
Chemical Contaminants
Commodities
Produce