The storage system of controled temperature lower than normal has again been recognized recently to be recommendable, since the system was effective to prevent degradation and deterioration of the quality as to chemical components as well as appearance from putrifaction and insect damage. The present paper describes some of observations on the growth of injurious microorganisms at lower temperature, to solve the problems found in the actual current system of the cereal storage.
The mixure of preservatives has been permitted in specified foods. These preservative mixtures were divided into five groups. (1) Mixtures of salicylic acid and esters of p-hydroxybenzoic acid. (2) Mixtures of benzoic acid, esters of p-hydroxybenzoic acid and methylnaphthoquinone. (3) Mixtures of benzoic acid, esters of p-hydroxybenzoic acid and dehydroacetic acid. (4) Mixtures of sorbic acid, nitrofurazone and nitorofurylacrylamide. (5) Mixtures of dehydroacetic acid and nitrofurylacrylamide. The mixtures of these preservatives were extracted and separated by solvent extraction method. Each component extracted was determined by ultraviolet absorption method. Nitorofurazone only was carried out by phenylhydrazin method. These analytical data are tabulated (Tables 4-8). Recoveries were found more than 95%, but that of nitrofurylacrylamide was less than 95%.
The methods for the detection and determination of nitrofurazone and nitrofurylacrylamide added in milk are described. These substances, extracted by dimethylformamide, were detected by color reaction with 1N sodium hydroxyde solution. The method for the determination of nitrofurazone was based on the formation of 5-nitro-2-furfural phenylhydrazone, which was estimated by colorimetric method, and nitrofurylacrylamide was determined by the absorbance measurement of that extracted with dimethylformamide.