This text reviews briefly the main methodologies of consumer-oriented design engineering used by the Food Industry. The most relevant implications of the recent developments in cognitive and neuro-science in this context are then analysed and it is concluded that incorporating the human, cognitive, dimension and its influence in food choice is the major challenge for further improvements. A vision of the "ideal final result" of a product design engineering sys- tem for foods is outlined and it is stressed that the development of kansei engineering in Japan seems a most promising emerging concept to be followed in this respect.
Dielectric properties of two types of unsalted frozen surimi (SA grade made on shipboard and K grade made in onshore plants) at 2450 MHz and 915 MHz were measured from 30°C to 30°C by the open-ended coaxial probe method. The values of dielectric constant and loss factor varied with temperature, being very small at low temperatures, whereas above the freezing point the values increased rapidly. Penetration depths which were calculated from the dielectric constant and loss factor also varied with temperature. Moreover, there was no difference in the dielectric constant or loss factor of the two kinds of surimi below the freezing point; there was a difference in the dielectric constant above the freezing point, however, due to the difference in moisture content of the surimi.
The color of wheat flour is an important commercial factor and improvement of the color characteristics of kernels is one of the breeding objectives in Japan. Methods were developed to measure color characteristics of both wheat kernels and wheat flour. Wheat kernels were fixed on a newly developed holder with light-curing resin, and a smooth cut-surface was prepared by a programmed cutting of a diamond wheel. Binder-free wheat flour was formed into cylindrical pellets to remove trapped air by repeated compression with a hydraulic press machine. Cut kernels and flour pellets were moistened and analyzed by a two-dimensional colorimetric method. Color changes of both specimens were stabilized after 3 h of moistening. And a comparison of their colorimetric results revealed the possibility of evaluating wheat flour color without milling the kernels. This is useful as an early generation selection method of breeding of wheat because the dissected embryo side retains the germination ability.
Time changes in electrical and rheological properties of carrot and potato cell tissues after freezing-thawing or chloroform-vapor treatment were compared to clarify the mechanism of cell tissue softening by freezing injury. Integrity of cell plasma membrane was analyzed by the electrical measurement and rheological properties of cell tissues were determined by the vibrating reed method. Changes in the rheological properties by the chloroform-vapor treatment were assumed to be caused only by the loss of turgor pressure, while those by the freezing-thawing were caused by loss of this pressure and injuries to the cell wall and intercellular structure. The change in the rheological properties of carrot and potato tissue by the freezing-thawing and chloroform-vapor treatment were compared to determine the contribution ratio of the loss of turgor pressure and injuries to the cell wall and intercellular structure, which are known as major causes of softening by freezing injury. Findings showed that the loss of turgor pressure due to plasma membrane injury is the main reason for cell tissue softening by freezing injury while injuries to the cell wall and intercellular structure have an auxiliary role.
Stress developments in cylindrically shaped food gels were comparatively investigated by applying uniaxial compression and torsional deformation up to fracture. While torsion tended to result in earlier fracture with lower fracture stress and strain values, the true shear stress vs. true shear strain curves determined based on uniaxial com-pression and torsion tests were in good agreement up to the point of fracture in torsion in most cases examined. A typical fracture plane was observed at an angle approximately π/4 radians with respect to the cylinder axis in both uniaxial compression and torsion, suggesting that those compressed and twisted gels fractured in shear and tension, respectively. Both fracture stress and strain values increased with increasing deformation rate, regardless of the mode of deformation. The present results confirm that torsion can be used for fundamentally assessing fracture characteristics of a material that deforms and/or fractures in an unpredictable manner under uniaxial compression.
We sought to determine the effects of sprout-induced α-amylase on the pasting properties of flour and starch in wheat grain. To accomplish this, we used grain from five winter and two spring wheat cultivars obtained by significantly delaying the harvest date. Furthermore, grain from one winter wheat cultivar was soaked in water for 24 h at 5°C and then stored up to 48 h at 20°C. α-Amylase activity and the pasting properties of flour and starch were examined in each wheat sample mentioned above. Extremely late harvesting was associated with higher α-amylase activity and lower peak viscosity of flour in general. However, little change in starch peak viscosity was observed during the late stage of development in most cultivars. A wetting treatment also indicated that an excess accumulation of α-amylase and a marked decrease in flour peak viscosity did not coincide with a large decline in starch peak viscosity.
The effect of weakly electrolyzed water (anode water and cathode water) on the properties of Japanese wheat noodles was examined. Instrumental measurements and sensory tests of the cooked noodles revealed that noodles made by kneading wheat flour with anode water were harder and springier than those made by kneading wheat flour with tap water. This suggests that anode water provides a favorable texture to the cooked noodles. Anode water promoted the dissolution of gliadin and glutenin subunits which participate in the formation of gluten-matrix, so that the texture of cooked noodles was improved by kneading the wheat flour with this water. When noodles were cooked in either anode water or cathode water, they showed less springiness compared with those cooked in tap water. The use of either anode or cathode water for cooking changed the gelatinization condition of starch, which affects the texture of the cooked noodles.
The properties of tofu prepared with weakly electrolyzed waters (anode and cathode waters) obtained by electrolysis of tap water were investigated. The use of cathode water increased the protein content of the tofu. The texture of tofu prepared with cathode and anode waters was softer than that of tofu prepared with tap water. No significant difference in the free sugar content was seen between the tofu prepared with electrolyzed and non-electrolyzed waters. However, tofu prepared with cathode water was evaluated as sweeter than that prepared with tap water in a sensory test. The content of total carbonyl compounds, which is related to the substantial taste of tofu, was higher in the tofu prepared with cathode and anode waters than in that prepared with tap water. These results show that the eating quality of tofu can be modified by using electrolyzed water (especially cathode water) for its preparation.
The protective effects of major boysenberry anthocyanins (BoAnt) against oxidative stress were investigated in streptozotocin (STZ)-induced diabetic rats. Increases in the concentration of plasma thiobarbituric acid reactive substances (TBARS), and in the liver 8-hydroxy deoxyguanosine (8-OH dG)/deoxyguanosine (dG) ratio and also in the liver GSSG/GSH ratio, which were all observed in STZ-injected rats, were restored or tended to be restored to the level of the control rats when a diet with BoAnt was given to the diabetic animals. The susceptibility of the liver homogenate of the diabetic rats to the oxidation by AAPH was relieved when BoAnt was fed to them. These results suggested that BoAnt was effective in protecting the development of in vivo oxidation involved with diabetes.
Recent studies of natural aromas have focused on only the lowest odor threshold compounds. In this study, we evaluated the volatile compounds of Japanese green tea, comparing the original aroma simultaneously input to the sniffing port method (OASIS) with the aroma extract dilution analysis method (AEDA). Geraniol, indole and linalool were classified in the low odor threshold by AEDA. Using OASIS, geraniol showed enhancement of the green character and indole showed strengthening the overall green tea odor, but linalool gave the same result as AEDA. On the other hand cis-3-hexenol, decanal and β-ionone were classified in the high odor threshold by AEDA, OASIS showed enhancement of the green, tea-leafy, and sweet characters respectively. We added these compounds to a Japanese green tea infusion and evaluated it. The results showed great similarity to the OASIS results. In conclusion, OASIS is an effective technique by which to evaluate mixtures of volatile compounds with original aromas.
Mixed whole human saliva contains 4-hydroxyphenylacetic acid (HPA), nitrite and polymorphonuclear leukocytes. Salivary leukocytes nitrated HPA to 4-hydroxy-3-nitrophenylacetic acid in the presence of nitrite, and phorbol myristate acetate stimulated the nitration. Quercetin and the glucosides, which are found in the oral cavity after ingestion of quercetin-rich foods, inhibited the leukocyte-dependent nitration. The inhibition by quercetin and the glucosides was in part due to the flavonol-dependent scavenging of nitrogen dioxide which was formed by myeloperoxidase-dependent oxidation of nitrite. Salivary components, SCN and uric acid, also inhibited the nitration. The above re-sults suggest that quercetin can cooperate with SCN and uric acid to prevent nitration in the oral cavity.
Vitamin U levels were determined on 26 kinds of food plants well known to be healthy vegetables in Asian or Western countries. Spinach showed the highest level of 45.2 mg/100 g DW followed by Pak-choi (34.3 mg/100 g DW)>kale (23.4 mg/100 g DW)>Sumssukbujaengi (19.8 mg/100 g DW)>leaf mustard (19.6 mg/100 g DW)>bud of aralia (19.3 mg/100 g DW)>broccoli (18.9 mg/kg DW)>asparagus (18.7 mg/100 g DW). Among Korean wild medicinal plants, Sumssukbujaengi showed the highest value followed by Sanmanul (a kind of wild garlic) with the level of 14.4 mg/100 g DW. For Chinese and Western cabbages, the level of vitamin U differed according to the parts of the plant such as core, middle and outside leaves. In both cabbages, level in the middle parts of leaves including midribs was the highest. As stated, the level of vitamin U was dependent on the part of the plant sample. Leaf parts of turnip and white radish showed higher value of 8.5 and 12.5 mg/100 g DW, respectively, than those of roots such as white radish in which levels were in the order of middle (11.3 mg/100 g DW), top (8.5 mg/100 g DW) and bottom (8.5 mg/100 g DW) portions in the white radish. In the analysis of amino acids, we did not find either a distinctive relationship between methionine and vitamin U synthesis or a significant connection between various free amino acids and vitamin U level in food plants.
The odor-active volatile compounds of porcine liver were collected by a simultaneous steam distillation–solvent extraction method (SDE). The extracted compounds were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The key aroma compounds of off-flavor in porcine liver were characterized using gas chromatography-olfactometry (GCO) technique. The volatiles identified included aldehydes (1.89%), ketones (0.62%), alcohols (0.61%), furans (0.11%), thiazoles (0.21%), phenols (0.31%), pyrazines (0.18%), esters (12.31%) and acids (80.06%). 1-Octen-3-one and hexanol are considered to be responsible for the intense and weak metallic odor, respectively, and other identified major volatiles with their odor note given in parenthesis were as follows : (E,E)-2,4-heptadienal (fishy), (E)-2-octenal (tallowy), (E)-2-nonenal (cardboard-like), (Z)-4-decenal (cardboard-like) and (E,E)-2,4-decadienal (deep-fried). It was also confirmed that the fishy and metallic flavor in liver was not completely removed even after subjecting to heat treatment. The metallic and fishy notes make up the whole liver-like off-flavor in porcine liver.
Effect of high pressure carbon dioxide treatment (35°C, 6.5 MPa) (HPCT) on the heat tolerance of bacterial spores was investigated. Spores of Bacillus coagulans and B. licheniformis were subjected to HPCT following heat treatment (80, 85 and 90°C for 30 min) (HT). Spores of both types were sterilized completely in 30 min-90°C HT after HPCT. These results indicated that HPCT greatly decreased the heat resistance of spores.
In order to utilize low-cost squid effectively as a functional material for food processing and preservation, squid protein hydrolysate (SPH) was prepared from 4 species of squid by protease treatment. Peptides are the major components (84–88%) of SPH. The protective effect of 5% SPH (dry weight/wet weight) on the freeze-induced denaturation of lizardfish Saurida wanieso myofibrillar protein (Mf) was evaluated on the basis of Mf Ca-ATPase activity and the amount of unfrozen water in Mf, which was determined by differential scanning calorimetry (DSC); the effect was compared with that of sodium glutamate. Mf with SPH showed markedly higher Ca-ATPase activity than did Mf without SPH (control) during frozen storage. Mf with SPH had a higher amount of unfrozen water than the control. These findings suggest that SPH stabilized water molecules in the hydration sphere of Mf and thus, suppressed freeze-induced denaturation of Mf. The effect by SPH was less than that by sodium glutamate.
The effect of palatinose intake on α1 brain wave generation was studied by human volunteer test. Twelve healthy volunteers were administered 40 g of palatinose or sucrose, and electroencephalogram (EEG) was made before and at 150 min after administration. The area of α1 wave generation on topographs increased after administration of either sugar, but there was a significant difference in the intensity between the palatinose and sucrose groups. Ten volunteers were administered 100 mg of theanine, which has a relaxing effect, in combination with 17.5 g of palatinose (T-P group), and EEGs were recorded before, at 60 and 150 min after administration. Though the area of generated α1 brain wave in the topographs increased in both groups (T-P and 17.5 g palatinose groups) after administration, the patterns of their increase differed. Nine volunteers were administered 5 g of palatinose, and EEGs were recorded before and at 150 min after the administration. The area of α1 wave generation increased slightly but less than that in 40 g palatinose group. The above results suggested that palatinose enhances generation of α waves and that its effect might be maintained longer than that of sucrose.
A system to evaluate the intestinal permeability for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was constructed with human intestinal Caco-2 cell monolayers. TCDD was added to the apical side of the cell monolayers and the basal TCDD concentration was estimated by using a HepG2 cell having a luciferase vector with a xenobiotic-responsive element in the promoter region. Addition of such food substances as chlorophyll to the apical side of the Caco-2 cell monolayers markedly decreased the apical-to-basal transport of TCDD. This system would be useful for use in searching for the materials having an inhibitory activity to intestinal TCDD absorption.
O/W type emulsions were prepared with salmon oil as lipid and soymilk or whole egg as an emulsifier at different pH, to know the effect of pH on the oxidation and flavor stability of mayonnaise-like emulsions. Emulsions were oxidized in the presence of hemoglobin as a catalyst at 20°C. Both emulsions prepared with soymilk and whole egg were stable at pH 4 to 6, when the oxidative stability of emulsions was estimated as the induction period. Volatile compounds produced during oxidation were quantified for emulsions at different pH. Total volatiles were highest at pH 4. Propanal was added as a typical volatile compound to emulsions at different pH. The quantity of propanal in the gas phase was highest at pH 4, while it was lowest in the liquid phase at pH 4. The inferior flavor stability of mayonnaise could be due to the high volatility of low molecular weight compounds at pH 4, but this is not true of the oxidative stability.
The seasonal and polyploidal changes of α-glucosidase (rat-intestinal) inhibitory activity in mulberry leaves were compared in 12 mulberry varieties. Enashi, Fusoumaru, No. 325 and Kenmochi which are classified as 3 major varieties in Japan were harvested in May or August as the field samples. Shimaguwa and the 3 different wild types such as Kuromiguwa, Nagamiguwa, Midoriguwa were harvested in May as the greenhouse samples. Some varieties harvested in the field or greenhouse indicated a difference in α-glucosidase. In the field Enashi was strong, while Kenmochi was rather weak. The seasonal changes of inhibition between May and August were differed among the varieties. The 3x variety in the field or greenhouse showed the strong inhibition within the same variety.