The availability, speed and affordability of personal computers (PCs) enable new possibilities in the education and training of Food Engineers. The use of PCs enables students to grasp complex concepts without getting tangled in computational details, use simulations and ask what-if questions to better understand and visualize phenomena or processes, and eliminate or minimize simplifying assumptions. Internet and World Wide Web make distributed learning possible. Available software are classified into three categories: generalized commercial software such as spreadsheets, semi-specialized but expensive software such as Aspen or MATLAB, and specialized software written by faculty/students in Food Engineering. There is a need to develop educational software by the latter group, since software for small audiences is not economical for commercial software companies. Examples of educational programs are given. A world-wide clearing house for software developed by faculty/students is suggested. The possible mechanisms of such an effort is discussed.

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Allergy occurring in those who are sensitized due to their day-to-day ingestion of some particular foods has deserved note in recent years, and novel ways of countermeasures are being studied internationally. In the field of immunology, close attention is now paid to anergy which is the antithesis of allergy. Food scientists and technologists, on the other hand, have been progressing a long a more practical path to produce hypoallergenic foods. This paper pinpoints the present state of the studies on cereal allergy and responsible factors (allergens), with special emphasis on the importance of creating hypoallergenic cereal products. Expected future roles of food science and technology in more extensively developing such countermeasures are also discussed.

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We investigated the stability of a monodispersed o/w emulsion and the uniformity of oil droplet distribution in an agar-based emulsion gel during successive stages of gel preparation. At each stage of the emulsion-sol preparation, almost no differences in the droplet diameter and number in excess of the range of measurement error were found. These results directly indicate that the monodispersity of the emulsion was maintained before and after heating of the agar sol. To evaluate oil droplet uniformity in the emulsion gel, sections of 5 mm in height were cut from the top, middle and bottom of the emulsion gel. No differences were found in the number of oil droplets and the coefficient of variation of droplet sizes in top, middle and bottom sections of the gels with oil volume fractions ranging from 0.01 to 0.27 in any of the emulsion gels.

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The surface activity, emulsion stability and foamability for two kinds of monodesmoside saponins of Sapindus mukurossi Gaertn (I and II) and the zeta potentials of emulsions prepared with these saponins in a water/kerosene system were investigated. There were no differences in the surface activity, foamability, emulsion stability or zeta potential of the emulsion droplet between the two kinds of saponins (I and II) of sapindaceae. The surface activity, emulsion stability and foamability of both I and II were higher than those of soyasaponin I (SI). The zeta potential of emulsion droplets prepared with I or II was lower than that prepared with SI. The water separation of both the I and II emulsions by creaming were higher than that of the SI emulsion.

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Freezing points of polyol-aqueous solutions (xylitol, sorbitol, maltitol, lactitol, and hydrogenated corn syrup) were measured in the high concentration (30-60%) range and compared with those of their corresponding reducing sugar-ones (xylose, glucose and corn syrup). The freezing point depression (ΔT) of the formers solutions except for the hydrogenated corn syrup tended to be smaller than those of the latter ones. These solutions were not subject to Raoult's law but successfully fitted to Weast's equation for ΔT in the non-ideal equation. Molecular weights or mean molecular weights of saccharides would generally be derived from the slope obtained by Weast's equation and those closely resembled the known chemical molecular ones. Also, ΔT was found to be proportional to the reciprocal of the mean dextrose polymerization.

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An experimental study has been carried out on the binary adsorption equilibria of various flavors and water for typical materials used in a box of a tobacco product. A flavor component of L-menthol, which was sublimated from the solid state, was found to be adsorbed onto the surfaces of each material without phase re-transition under its unsaturated condition. For tobaccos, papers and filters, flavors with a water soluble or polar nature were adsorbed to a greater degree than otherwise, while for the activated carbons, this dependence showed the opposite tendency except for L-menthol. These behaviors of the binary adsorption equilibria of various flavors and water are explained as follows; (a) for the tobacco and paper, the flavors were mainly adsorbed by the solution in the adsorbed water, and to some extent, on the hydrophobic sites of the material's surface, (b) for the filter, they were adsorbed on the hydrophobic sites such as the acetyl group inside the tow, (c) for activated carbon, their adsorption was attributed to the filling of flavor molecules in the inner surface of the micropores, but depended on their size.

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A novel membrane emulsification method was used to prepare corn oil/water (O/W) emulsions (25 wt% oil phase) with sharp particle diameter distribution. When pre-emulsified O/W emulsions were used as dispersing fluids instead of the oil phase (corn oil+emulsifier), the membrane emulsification was carried out easily with a high emulsifying rate up to 3.5 m³/(h·m²-membrane). Mean particle diameters of the emulsions were about twofold those of the mean pore sizes of the porous glass membranes used. The particle diameter of the emulsions decreased with increasing applied pressure or flux of the pre-emulsified emulsion through the membrane. Because of the high stability of the membrane emulsified emulsion particles, little change in particle diameter distribution occurred over several weeks. The kind of emulsifying agent influenced the particle diameter distribution and the creaming rate.

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The water soluble antioxidant (partial by purified WSA: p-WSA) was partially purified from the supernatant fraction of okara, a by-product of tofu manufacturing. The contents of total phenolics, sugar and protein in p-WSA were 0.11%, 0.14% and 74.8%, respectively. The ninhydrin reaction was positive, and the ultraviolet absorption spectral λ max values were 264 nm and 280 nm. The antioxidant activity of p-WSA was determined by two different systems. The p-WSA showed remarkable antioxidant activity in a linoleic acid system and had the same effect as mixed tocopherols; however, it appeared weak in active oxygen method systems. The p-WSA showed a strong synergistic antioxidant effect with tocopherol but appeared weak with citric acid. The antioxidant activity was completely stable even after heating at 100°C for 1 h. Isolation and identification of the structure of p-WSA are currently under way.

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A separation method for piperine and its isomers (chavicine, isochavicine and isopiperine) from a photoirradiated mixture of piperine, in solution and in suspension, by high performance liquid chromatography (HPLC), was investigated to clarify the relationship between the disappearance of the pungency in older, ground pepper and the photoisomerization of piperine. Piperine and its isomers were separated on a Sumichiral OA-2000 column with hexane/dichloromethane/ethanol (48/16/0.8) as an eluting solvent. Their structural elucidation was carried out using nuclear magnetic resonance spectroscopy and HPLC atmospheric pressure chemical ionization mass spectrometry (LC/APCIMS). Although the increment in the three isomers in commercial ground pepper after exposure to sunlight was observed by monitoring the MH⁺ ion on LC/APCIMS, the degree of increase varied very little. It is questionable whether the disappearance of the pungency in older, ground pepper is derived from the formation of tasteless isomers by photochemical changes in piperine.

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Anthocyanins were isolated from 19 kinds of vegetables and fruits. Individual anthocyanins were analyzed by HPLC using a photodiode array detector and were examined for the heating and ultraviolet irradiation stabilities of these anthocyanins. This report deals with the relationship between anthocyanin composition and heating or ultraviolet irradiation stabilities of anthocyanins. Stable anthocyanins showed many anthocyanin peaks and a high ratio of acylated anthocyanin peaks. This result shows that the anthocyanin composition and the rate of acylation affect the stability of anthocyanins.

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A spectrophotometric microtiter-based assay was established for quantification of the ability of UHT-treated milk to reduce 3'-{1-[(phenylamino)-carbonyl]-3,4-tetrazolium}-bis(4-methoxy-6-nitro)benzenesulfonic acid hydrate (XTT). Under the optimized conditions, 40 μl of a milk sample was mixed with 60 μl of 0.5 mM XTT solution (pH 7.0) saturated with menadione in each well of a 96-well microtiter plate. The formed XTT formazan in the reaction mixture was determined by an increase in the absorbance difference between that at 492 nm and at 600 nm during the incubation for 20 min at ambient temperature. The use of the absorbance at 600 nm as a reference wavelength permitted the determination of XTT formazan without any interference from the turbidity caused by the addition of the milk sample. The present microtiter plate assay could differentiate two kinds of UHT-treated milk with a different extent of thermal treatment. In addition, the reducibility of the UHT-treated milk gradually decreased during storage dependent on the period or temperature. The method was very convenient and economical; it is promising as a method of estimating the extent of the heat treatment of milk and the storage conditions.

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Ume fruit was brined with 0, 0.3, 0.6 and 0.9% (based on fruit weight) calcium hydroxide for 36 days and subsequently exposed to the sun for 8 days. The water content and titratable acidity decreased, and the sodium chloride concentration increased in the fruit from all lots during brining. During exposure to the sun while immersed in water with a film package, the sodium chloride concentration and titratable acidity both decreased, and the water content increased in the fruit from all lots. The L- and b-values of the fruit surface decreased, the a-value increased, and the chlorophyll content decreased markedly in the first 3 days in the fruit from all lots during brining. The L- and a-values increased after sun exposure, these values being larger with increasing calcium hydroxide concentration. The ‘lightness’ and ‘redness’ of the sun-exposed ume samples were evaluated according to a 7-level numerical scale in comparison with the brined ume samples with the same calcium hydroxide concentration, and the result was subjected to the t-test. A significant difference between these two groups was at the level of p<0.001 with every calcium hydroxide concentration. The sun-exposed ume samples were lighter and redder than the brined ume samples. The ‘redness’ could be discriminated at the significance level of p<0.01 between paired samples, except with a 0.6-0.9% calcium hydroxide concentration in the brined ume sample and 0.3-0.6% in the sun-exposed ume sample. A coefficient of correlation between the scale of ‘redness’ and the hue value was recognized with r=−0.915 and r=−0.947 (both p<0.05) for the brined and sun-exposed ume samples, respectively. It was confirmed that the ‘redness’ was increased by sun exposure after brining and, furthermore, the hardness was unchanged by sun exposure. Consequently, it is suggested that the sun-exposure step can be introduced into the salted ume processing in order to intensify the red coloring.

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Ume fruit brined with 2.5 kg of brine solution mixed with calcium hydroxide (3 g Ca(OH)₂/1 kg of fruit) was either non-exposed or sun-exposed and subsequently colored with new coccine (0.004-0.1%), acid red (0.0008-0.04%), red cabbage color (0.1-10%) or perilla color (0.1-10%) colorant. A comparison was made between the sun-exposed and non-exposed samples using Hunter L-, a- and b-values as optical measurements and by sensory evaluation as an organoleptic measurement. It was confirmed that the color change with each colorant had almost reached equilibrium after 7 days. It was also noticed that the dye effect of red cabbage color and perilla color was weaker than that of new coccine and acid red. The L- and a-values of the sun-exposed samples were higher than those of the non-exposed samples, although the b-values indicated no clear difference between the sun-exposed and non-exposed samples with any colorant. The sun-exposed samples were evaluated as being lighter, redder and more preferred than the non-exposed samples with all colorants by the visual-sensory test. The degree of difference in ‘redness’ was numerically evaluated, and the ‘redness’ effect ratio on the sun-exposed samples to the non-exposed samples with the same colorant concentration was 1.1 for new coccine, 1.7 for acid red, 2.1 for red cabbage color and 1.5 for perilla color. This study clarifies that even if the colorant concentration is reduced, the same level of redness for ume fruit could be obtained with sun exposure before coloring. It is proposed that sun exposure will contribute to the coloring of salted ume fruit.

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