APPLICATION OF RADIOCHEMISTRY IN FOOD PROCESSING RESEARCH. PART I. RADIOISOTOPIC TRACER TECHNIQUES FOR DETECTION AND MEASUREMENT OF DETERGENT RESIDUES ON WASHED FOODS. Annual Report

Technical Report · Sun Apr 01 04:00:00 EST 1962

OSTI ID:4714513

Mercer, W A

In view of the wide spread use of detergents and wetting agents in the food industries and the great need to employ these washing aids in more effective removal of microbial, chemical, and, possibly, radioactive contaminants, an extensive series of food washing studies was undertaken. The studies were intended to determine to what extent commercial food washing procedures remove residual detergent and to define the washing and rinsing conditions required for thorough cleaning of fruit and vegetable products. Radioactive surfactants and tracer techniques were used. The investigation gave particular attention to the washing of green and white asparagus selected because it is industry practice to detergent wash this vegetable. The effect of changes in washing and rinsing conditions was measured in terms of removal of bacterial contaminants, and deposition and removal of radioactive detergent residue. The accumulated experimental data indicate the following: (1) Type of detergent most effective in removal of bacterial spores and the effect of detergent type, anionic or nonionic, on the concentration of bound detergent residue. (2) Most effective combination of contact time, temperature, and pressure of application of the detergent solution for removal of bacterial spores from the test foods. (3) Most effective rinsing conditions, including volume, pressure of sprays, and temperature of rinse water, for adequate removal of bacterial spores and detergent residue. (4) Washing and rinsing conditions which affect the concentration of bound detergent residue in or on the washed foods. A second phase of the contract work was concerned with the use of detergents in washing olives, previous to brine storage. The anti-shrivel effect and improved fermentation of the detergent wash were advantages in addition to the more effective removal of contaminants. Use of radioactive detergent in experimental washing studies showed that all significant amounts of detergent residue were removed by subsequent processing of the olives. However, where radioactive detergent was added directly to the storage brines high concentrations of bound residue were found in the olives after final processing. A series of experiments was performed to study the effect of wetting agents when added to the caustic solutions used to peel apricots, peaches, and tomatoes. Experimental results and observations indicated use of wetting agents in peeling solutions made possible the following: (1) more uniform peeling; (2) higher product yield; (3) use of lower caustic concentration, and (4) reduction of rinse water volume required for removal of excess caustic from the peeled product. Particular attention was given to the extent of infiltration and removal of the wetting agent during the peeling and rinsing operations. The experimental results showed that some diffusion of wetting agent irto peripheral tissues of the peeled fruit and tomatoes took place. However, adequate rinsing of the peeled products removed all but a trace concentration of the radioactive residue. Under the conditions of these experiments, the average concentration of residue was less than 0.05 ppm in peeled and washed peaches and tomatoes. This is considered not to be significant from the standpoint of food adulteration. (D.L.C.)

• Research Organization: National Canners Assn. Western Research Lab., Berkeley, Calif.
• NSA Number: NSA-17-027637
• OSTI ID: 4714513
• Report Number(s): SAN-1020
• Country of Publication: United States
• Language: English

Related Subjects

BACTERIA
CLEANING
DETERGENTS
DIFFUSION
EFFICIENCY
FOOD
FRUIT
INDUSTRIAL APPLICATIONS OF ISOTOPES AND RADIATIONS
LABELLED COMPOUNDS
PRESSURE
RADIOCHEMISTRY
RADIOISOTOPES
RESIDUES
SPUTTERING
STORAGE
TEMPERATURE
TISSUES
TRACER TECHNIQUES
USES
VEGETABLES
VOLUME