The chemical method for measuring the degree of rancidity in food fat, as previously reported, was applied to aged fried rice crackers soaked in antioxidant-containing oils. The rice crackers were fried with soybean oil, corn oil, and lard at 240°C. After the oils in these fried rice crackers were extracted with hexane, the defatted rice crackers were soaked in oils to which 0.01% of citric acid, 0.005% of BHA, and 0.005% of BHT were added. Thus, the contents of antioxidants in oils in fried rice crackers were assured. Then, these fried rice crackers were aged under various conditions, such as in dark at 35°C and 62°C, and in light at 25°C. The development of rancidity in these fried rice crackers was measured by sensory evalution by an experienced panel and chemical tests such as the measurement of peroxide value, carbonyl value, and volatile carbonyl value. The results resembled to that of the previous paper, except the term to reach rancidity. Addition of antioxidants retarded the development of rancidity, but did not change the relations between the chemical characteristics such as peroxide value, carbonyl value, volatile carbonyl value and flavor score.
In various foods, it is often experienced that a presence of oil in food complicates the taste of the foods and makes it mild and sometimes even very delicious. However, this effect of oils on the taste of food has not been studied systematically. This paper deals with the effect of oil on so-called “five tastes”. Sugar, salt, tartaric acid, quinine hydrochloride and monosodium glutamate were chosen as the representative of five tastes, namely sweet, salty, sour, bitter and glutamate taste (“Umami”, in Japanese), respectively. Taste panel consisted of about 15 persons, who were the stuff of our laboratories and our students. Two series of experiments were carried out. 1) Taking the case of sweet taste, emulsions typed of w/o and o/w of 5.46% aqeuous solution of cane sugar and corn oil were made. Each of 7.20, 6.28, 5.46, 4.75 and 4.13% solutions of cane sugar were also made. The panel made the guess which solution were equal to the sweetness of these o/w and w/o emulsions. Such experiments were also done on other four tastes as well as on some real foods such as margarine, cream and mayonnaise. 2) Also taking the case of the sweet taste, 7.20, 6.28, 5.46, 4.75 and 4.13% solutions of cane sugar were made, while o/w and w/o emulsions of these solution and oil were made. The panel carried out the difference tests on these series. The number of the errors in these experiments was compared. As the results, it was found that intensity of tastes were much decreased in the w/o emulsion. In the difference tests on the emulsions of both w/o and o/w type it was much difficult to describe the differences than those on mere ageous solutions. These results seem to be able to explain to some extent the general belief, “oil makes the taste of food mild and delicious”.
In order to calculate the work of adhesions in a system comprises of soil/dispersing media/polymer interfaces, the authors calculated the surface tension of solids and discussed these calculating methods. Surface tension of 12 liquids and their contact angles on paraffin wax, polyethylene and polystyrene were measured. The dispersion component and polar component of surface tension of these liquids and solids were calculated by applying Fowkes' equation, extended Fowkes' equation (Owens and Wendt's equation) and Wu's equation. (Table-1, Table-7) The Wu's equation proved to give the most reasonable surface tension component values for the samples chosen to discuss the detergency process.
Polymorphism of 1, 3-diacylglycerols (on the carbon number of each acyl group, 4 kinds are even and 2 kinds are odd) was examined by differential scanning calorimetry (DSC) and IR spectrometry. 1) Polymorphism of 1, 3-diacylglycerols by DSC indicates endothermic and exothermic peaks during transition from β-a to β-b type. Heat of this transition is extremely small. As the length of the molecularchain becomes shorter, transition to β-b type occurs during elevation of temperature in DSC. Consequently, transition from β-a to β-b can be observed more sharply, the faster the elevation of temperature during DSC measurement. 2) Transition temperatures were measured and data are given in the accompanying table. Fusion temperature of β-b type is the same as that reported, but the transition temperatures from β-a to β-b type as measured by DSC are lower by 12.2°C (C18) to 17.3°C (C14) than those reported. 3) Time required for transition of 1, 3-diacylglycerols of which each aryl group has odd number of carbon atoms was shorter than that of 1, 3-diacylglycerols of which each acyl group has neighboring even number of carbon atoms. Relationship between the time required for transition and molecular chain length shows alternation. 4) 1-Mono- and 1, 3-di- and tristearoylglycerols with the same acyl group were heat treated at 50°C and the time required for transition was compared. The time required for transition of 1, 3-distearoylglycerol was 10h and equal to that of tristearoylglycerol and markedly shorter than that (80h) of 1-monostearoylglycerol.
Various derivatives of benzoic acid and hydroxybenzoic acid were prepared. Corrosion test for cutting fluids characterization of these compounds were examined. Triethanolamine salts of m-iodobenzoic acid and other iodo-compounds have excellent properties.
Mettler dropoing point (MDP) and softening point (MSP) were compared with clear point (CP), Wiley melting point (WMP) and softening point (SFP) of JIS method as to two kinds of mixed fats. One was the mixture of hardened beef tallow and soybean oil, and the other was the mixture of hardened coconut oil and hardened fish oil in various ratio, And then, MDP, MSP and SFP, and WMP (only for fats) were measured with plastic fat products, such as margarine, and their separated or melted fats. Results obtained were as follows : 1) The measured values of MDP of mixed fats agreed approximately with CP and WMP values, and the deviation of measured values was very small. 2) In mixed oils, same as in hardened oils reported previously, SFI curves of the mixture containing a larger amount of liquid oil component or hardened coconut oil showed a wider temperature range in the low SFI region, their MSP became lower than MDP, and measured values have tendency to deviate more. MSP was assumed to indicate the point between SF 1/and 2. 3) In solid fats, excluding hardened coconut oil and its mixture, a positive linear correlation was observed between MSP and SFP at 0.1% level of significance. 4) MDP of fats obtained from plastic fat products agreed approximately with WMP but MSP generally showed a slightly lower values than MDP, and this difference was relatively large in household margarine. On the other hand, MDP and MSP measured in the products were somewhat higher than those of the fat components, and this difference was greater in household and bakerly margarines than in butters and shortenings.
Water soluble polymers were prepared by the reaction of poly (methyl acrylate) (PMA) with dibasic amino acids such as L-arginine or L-lysine (LS) in the presence of alcoholic sodium hydroxide. These polymers react with copper (II) ion in dilute aqueous solution to form complexes which have a good foaming ability. Then copper (II) ion can be removed and recovered by a foam treatment. Better results could be obtained when the (PMA-LS) reaction product was used. More than 99.9% of cadmium and cobalt or more than 99% of lead and nickel were also removed by (PMA-LS) reaction products.