In food manufacturing processes, food products themselves adhere as soil residues on the surface of the equipment. Adherence of soil deposits causes contamination with microorganisms, which then brings the equipment into unsanitary conditions unless they are properly removed after the end of processing. Soil deposits in heat exchangers during processing markedly increase hydraulic and heat transfer resistances and thus removal of the soil deposits from the wall, i. e., cleaning of the equipment is conducted frequently. The author's first study on the rinsing of membranes fouled with milk protein that had been conducted in T. U. Mi nchen stimulated his further interest in the field of adhesion of soils on the solid surface and its cleaning of the fouled surface. In this review, the author summarizes his studies on the fundamental aspects of soil adhesion on the metal surface and cleaning, which were accomplished with his colleagues and students. In particular, the adsorption mechanism of proteins on the metal oxidized surface is investigated from the standpoint of the molecular level. The reason for the very strong interaction of proteinaceous soils to the metal surfaces is revealed, focusing to the interaction with the surface and conformational change in the adsorbed state. The author also summarizes the rinsing velocity and cleaning velocity during caustic and enzymatic cleanings in addition to radical cleanings that were developed by the author and his colleagues.
In order to stimulate the utilization of carcasses of spent laying hens and to avoid disposal of them as industrial waste, we have used these carcasses as a source of functional food material. The chicken extract prepared from the carcasses contains antioxidant dipeptides, anserine and carnosine (ACmix) which consist of histidine and β-alanine. We have also developed the manufacturing procedures for extraction, separation and purification of these peptides at different purity levels using ultrafiltration, nanofiltration and in combination with the membrane technology and ion-exchange chromatography and investigated the antioxidant activity of ACmix using a protein-degradation assay with three reactive oxygen species (ROS) . As a result, we produced four kinds of chicken extracts enriched with ACmix for different needs in food processing and determined the characteristics of antioxidant activity of ACmix which is different from other botanical antioxidants. In this paper, the antioxidant effect of ACmix in combination with other botanical antioxidants on normal volunteers is also described.
Distribution of absorption power inside the heated material in the microwave oven is analyzed using parallel FDTD method. In the analysis, the microwave oven is modeled on an industrial one and the model solution (starchy solution and salted starchy solution) simulated food as the heated material. And also, temperature distribution of the model solution in the microwave oven was measured using iodinated solution and thermography. As a result, trends of calculated absorption power distribution and measured temperature distribution agreed well, and it is confirmed that parallel FDTD method for these problems is valid. Moreover, it is understood that middle of cup is high temperature and edge area also becomes high-temperature with the salted solution. We could get the tendency of the absorption power distribution of the model solution and could provide the fundamental data of the uniform appertization.
Freezing-thawing-dehydration technique is expected as a safe and energy-saving method for the treatment of food waste. A test apparatus was made by combining an electric cleaning machine with centrifuge and a refrigerator for the treatment of food waste in several kilogram scale. Food waste was frozen at -20°C, thawed at room temperature, and centrifuged at 142 xg. Twenty-five food waste samples, including vegetables and fruits with skins and cores, and gel materials, were treated by this apparatus. As a result, the average water content decreased from 88.38% to 74.57% to reduce the residual weight fraction down to 46.62%. In addition, food wastes and leftovers of 130 meals for 3 days in“Practice of Feeding Management II” a practical exercise in J women's university, were effectively dehydrated to reduce their average weight to 53% except 1 leftover. Freezing-thawing-dehydration treatment prevents decomposition of food waste free from offensive odor. Thus this method is expected to be applicable widely for recycle, transportation, and incineration of food wastes.
The contents of tea leaves ingredients were measured by using visible and near infrared reflection spectra. Fresh tea leaves were processed by withering, rolling, fermenting and drying. At each stage in the process, the samples were collected, and the contents of amino acids (Asp, Glu, Theanine, Arg) and polyphenol compound (Catechin) in them were measured chemically. The near infrared reflection spectrum of each sample was also measured. The contents of amino acids and catechin were able to be determined by using the values of spectra over a short period of time (a few seconds) . In the process, the color of leaves changed from green into brown, and the change was measured by the visible light reflection spectrum. The spectrum showed that the peaks of blue, green and red became small as the process advanced. It is thought from the above results, that we can apply the method of the near infrared and visible light spectra to the control of the tea manufacturing process.
This paper was examined the optimal extraction conditions of bioactive substances, cinnamic acid and chrysin from a Chinese propolis by using super-critical carbon dioxide (SC-CO2) . Cinnamic acid was extracted at lower pressure and shorter time than chrysin. The optimal extraction temperature for cinnamic acid and chrysin was 310K. It was suggested that differences of extraction behavior was caused by solubilities of these substances.
The effect of enzyme addition for the sedimentation activity of solid particles (mainly starch and bran) in waste water derived from a rice washing and manufacturing plant is described to decrease water treatment costs and reuse the ingredients of such waste water. Sedimentation of solid particles in waste water was highly dependent on enzyme concentration, temperature, and duration: the highest sediment ability (SV60: 43 (%) and SVI: 7.2 (ml⋅g-1) ) was obtained by the addition of protease M (acidic protease and pronase were contained) under 30°C and 24h duration. The total carbon (TC) concentration in the supernatant after enzyme treatments and sedimentation was almost the same value as the supernatant of waste water after centrifuge and less than 15% of the stock waste water without enzyme addition. Moreover, in the results of surface electron charge analysis, surface electron charges (mV) of solid particles in wastewater were increased by enzymatic treatment, and highly correlated values (r=0.848) with SV60 (%) were observed. These results suggest the occurrence of sedimentation and the concentrate of solid particles in waste water by the addition of enzymes as a result of the strong negative electron charges in solid particle surface and electrostatic interaction such as adsorption phenomenon.
An M0 number, which is a dimensionless formula of the film momentum transfer coefficient m0 and reverse of the dimensionless film thickness of flow, was proposed. The M0 numbers deduced from the known theoretical and experimental equations of momentum transfer phenomena for flows in a pipe and around a sphere were compared to the Nusselt numbers, Nu, and Sherwood numbers, Sh, for the corresponding heat and mass transfers, respectively, and a good analogy was found among them. The phenomena of momentum transfers were also simply explained using m0 and the M0 number. The author expects that these findings might be useful for improving the education of fundamental chemical engineering, food chemical engineering, and biochemical engineering.