In the powdered food, because there is a strong cohesion and low fluidity in the fine powder, a problem occurs during production of the weighing and filling and when dissolved soup with hot water. As a solution, we generally granulate the fine powder and make up the granules. In the fluidized bed granulation process of powdered food, which is one of the granulation technologies, aqueous solution is usually sprayed as a binder to the powder to grow the granules, however, increase in the moisture content of granules often spoils the product quality and elongates successive drying period. We developed the efficient granulation technique by using the Aqua-Gas Binder (Steam-Water Two-Phase Binder) as the binder of the fluidized bed granulation. In instant corn soup, granules of the same size are formed in a small amount of water of about 30％ by aqua-gas binder. The characteristics of the granulated granules were found to have excellent fluidity and solubility as compared with the liquid binder.
This brief overview covers some important aspects of microchannel (MC) emulsification, especially for food-grade applications. We introduce typical MC emulsification systems; fundamental characteristics of their droplet generation; and preparation of food-grade monodisperse emulsions, microparticles, and microcapsules. Major advantages of grooved MC emulsification plates include detailed direct observation of droplet generation from parallel MCs and a wide droplet size range. Straight-through MC emulsification plates are advantageous for higher productivity of monodisperse emulsion droplets. The uniquely mild droplet generation for MC emulsification exploits interfacial tension dominant at the micron level, suppressing degradation and denaturation of heat- and shear-sensitive emulsion components. Information on devices and operating parameters affecting the resultant droplet size is summarized, and effects of properties of MC array surfaces and emulsion components on droplet generation behavior are discussed. Layer-by-layer (LBL) deposition improves the stability of monodisperse oil-in-water (O/W) emulsion droplets prepared by MC emulsification. Coating with a maximum of seven layers of surface active components with alternating positive or negative charges changed the ζ-potential of the oil droplets, depending on the electrostatic properties of the outer layer. Several combinations of differently charged surface-active components have already been successfully applied for LBL deposition.
The antifungal activity of nine fatty acid salts (butyrate, caproate, caprylate, caprate, laurate, myristate, oleate, linoleate, and linolenate) was tested on the spores of Penicillium pinophilum NBRC 6345 and Penicillium digitatum NBRC 9651. Potassium caprate showed the strongest antifungal activity at 4 log-units. At incubation times of 180 min, potassium caprylate and potassium laurate showed antifungal activities of 2 log-units against P. pinophilum NBRC 6345. These results suggest medium-chain fatty acid salts showed the highest antifungal activity. The minimum inhibitory concentration of potassium caprate against P. pinophilum NBRC 6345 was 175 mM, and >175 mM for other fatty acid salts. When mixed with short-chain fatty acid salts (potassium butyrate, potassium caproate) or medium-chain fatty acid salts (potassium caprylate or potassium laurate), potassium caprate caused a 4 log-unit reduction in fungal growth; however, when mixed with long-chain fatty acid salts (potassium myristate, potassium oleate, potassium linoleate, or potassium linolenate) it had no antifungal effect. Thus, long-chain fatty acid salts inhibited antifungal activity of C10K. We also evaluated the ability of C10K to inhibit fungal growth on orange rind. C10K effectively inhibited P. pinophilum NBRC 6345 growth on orange rind. Thus, C10K shows promise as an antifungal agent.
Our aim was to assess the increase in amylase production in a novel submerged-culture system (involving co-culture of filamentous fungi) and the effect of medium composition on the amylolytic activity. Filamentous fungi, Aspergillus oryzae (HI-G strain) and Rhizopus arrhizus (P20 strain) were used asα-amylase and glucoamylase- producing organisms, respectively. The initial concentration of nitrogen and carbon sources, and the ratio of spores to mycelial weight of A. oryzae and R. arrhizus were found to influence the activity of amylolytic enzymes. Maxim enzymatic activity was achieved when initial maltose and ammonium acetate concentrations were 3％ and 1.29％ (w/v), respectively. Under these cultivation conditions, the cell concentration was 0.62 g per 100 mL, and glucoamylase andα-amylase activities were 675 and 4.68 U/mL, respectively. In addition, agitation speeds (50, 125, 200, 275, 350, and 500 rpm) in a 5-L jar fermenter affected the enzyme activity; an increase in glucoamylase production was obtained at 200 rpm after 120 h. These results indicate that high production of glucoamylase andα-amylase can be attained in a system of submerged co-culture of A. oryzae and R. arrhizus.
Lactic acid bacteria primarily perform lactic acid fermentation by utilizing monosaccharides such as glucose. However, the polysaccharide fructan, which is the main component of garlic, generally cannot be fermented. We recently investigated fructan-utilizing bacteria to create lactic acid bacteria-fermented garlic food and isolated the Lactobacillus plantarum S506 strain from pickled shallots. We were able to efficiently perform lactic acid fermentation with the S506 strain using garlic fructan as the only source of carbohydrate. The fermented garlic extract obtained with the isolated S506 strain as a starter markedly increased interleukin-12 (IL-12) production, an indicator of innate immune enhancement, in experiment using J774.1 macrophage-like cells derived from BALB/c mice. The main active ingredient in this IL-12 production-promoting action was suggested to be a component newly generated through fermentation. This lactic acid bacteria-fermented garlic food with a newly added immunological function is expected to be useful for maintaining health.
Kinko-imo is a dried sweet potato belonging to the orange sweet potato family with an old origin. It is a distinctive product of Shima, an area in Mie prefecture. In this study, we tried manufacturing the imo-shochu (sweet potato spirit) from kinko-imo (SG) for the purpose of finding useful alternatives. Simultaneously, we tried manufacturing another kind of imo-shochu (SR) which utilizes the skin-cambium part discarded in the manufacturing process. The flavor properties of SG and SR were confirmed by comparing the flavor compounds by subjecting the three existing products to the use of gas chromatography mass spectrometer (GC/MS) and by factor analysis of the quantitative value of these compounds. Furthermore, those characteristics could be reconfirmed by the sensory evaluation. Thereby concluding, that each of the two imo-shochu are distinct in their prospective flavors.
In the production of hot-filling tomato juice products, which pH value are below 4.6 and distributed at normal temperature, the heat sterilization condition is setting at 121℃ for 0.7 min with Bacillus coagulans as an indicator, and it is widely used throughout the world. This study covered the three studies, 1) investigate bacterial spore contamination level of raw tomato material, 2) discover the best heat sterilization indicator, and 3) set the heat sterilization conditions in order to determine the ensured commercial sterility. In the production of hot-filling tomato juice products, which pH value are below 4.6, B. coagulans is unlikely to cause deterioration. Tainted tomatoes are often contaminated by Bacillus subtilis group and Genus Thermoanaerobacterium. In this repot, spores of Genus Thermoanaerobacterium, which is identified from spoiled tomato juice and have been known to cause deterioration, should be used as a heat sterilization indicator for hot-filling tomato juice products. We used the heat resistance of hot-filling tomato juice (pH 4.6) with Genus Thermoanaerobacterium as an indicator. The required heat treatment conditions for proper sterilization were a D121℃-value of 0.3 min, a z-value of 8.2℃, and an F121℃-value of 1.5 min (D value×5). As a result of the above findings, the current heat sterilization conditions with 121℃ for 0.7min are not sufficient for proper sterilization.
In the previous study, we reported it is required for hot-filling tomato juice products which pH value are below 4.6 and distributed at normal temperature, that the heat treatment at 121℃ for 1.5 minutes, based on spores of Genus Thermoanaerobacterium as an indicator. As a results of the previousstudy, the current sterilization conditions at 121℃ for 0.7 minutes were insufficient for proper sterilization. The objective of this study is to aim at easing the heat commercial sterilization conditions for tomato juice with a low pH control in the process of mass production. Our new findings were as follows. The required sterilization conditions were a D121℃-value of 0.12 minutes, a z-value of 11.2℃, and an F121℃-value of 0.6 minutes (D-value×5) based on the condition under lower pH 4.4 as a successful heat sterilization indicator for B. subtilis group. Because the growth of Genus Thermoanaerobacterium spores are inhibited in tomato juice products under the above pH condition.
This study investigates the effect of the texture of agar gel as a model solid food on gastric digestion using a human Gastric Digestion Simulator (GDS). The GDS, which simulates gastric peristalsis, can investigate physical digestion phenomena such as disintegration of solid foods. Agar gels with different fracture stresses (56 to 219 kPa) and constant fracture stain (29%) were prepared by varying the agar concentration (1.5 to 4.5 wt%). Direct observation demonstrated that agar gel particles initially cut to a 5.0 mm cube gradually reduced in size and broke down into random shapes during simulated gastric peristalsis. The size distribution of the agar gel particles after the digestion experiment was analyzed using the sieving method. The fraction larger than 2.36 mm, which corresponds to the pylorus size, decreased with time: the wet weight ratio of that fraction to the total amount of agar gel particles was 18.0% at 180 min in the case of 1.5 wt% agar gel. The agar gel concentration did not affect the size distribution after 180 min, which shows that fracture strain plays a more important role in agar gel digestion. Our results provide useful information about the relationship between solid food texture and gastric digestion.
Adsorption isotherms of hydrophobic substances (methylparaben, coumarin, vanillin, isovanillin, and caffeine) onto a chromatographic organic monolith were measured at 24℃. Adsorption isotherms of coumarin and caffeine were linear and were expressed by the Henry equation. On the other hand, the isotherms of methylparaben, vanillin, and isovanillin were non-linear and could be expressed by combining the Henry and Langmuir equations. Among the adsorbates having almost the same molecular masses, vanillin was adsorbed the most on the organic monolith, and methylparabene followed. The adsorbate hydrophobicity was not a main parameter reflecting the adsorbability, but any specific interaction between the adsorbate and the monolith would play an important role on the absorbability onto the monolith.
Reviews: Workshop on New Trends in Food Technology