• Food Science and Biotechnology
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• v.15 no.1
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• pp.133-137
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• 2006

Wheat gluten-chitosan composite film (WGCCF) can prevent moisture migration and enhance the antimicrobial properties of gluten in intermediate-moisture foods like sandwiches. To mimic the structure of actual sandwich-type products we developed multi-layer food models, where moisture content and water activity differ. Water activity gradients direct moisture migration and therefore determine product characteristics and product stability. A 10% wheat gluten film-forming solution was mixed with chitosan film-forming solution (0-3%, w/w) and evaporated to generate WGCCF. Addition of 3% chitosan enhanced the mechanical properties of the film composite, lowered its water vapor permeability, and improved its ability to protect against both, Streptococcus faecalis and Escherichia coli, in a 24 hr sandwich test (reduction of 1.3 and 2.7 log cycles, respectively, compared to controls). Best barrier and antimicrobial performance was found for 3% chitosan WGCCF at pH 5.1. Film of this type may find application as barrier film for intermediate-moisture foods.

• Korean Journal of Food Science and Technology
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• v.20 no.3
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• pp.363-370
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• 1988

An attempt was made in this study to investigate the possibility of processing oyster and sea mussel into an intermediate moisture food. To obtain a palatable and instant product, shucked samples were heated in soy sauce for 5 min., heated in seasoning solution for 10 min., and then dried by the method of hot-air blowing for 4-6 hours at $40^{\circ}C$. Optimum seasoning solutions consisted of 2% monosodium glutamate, 3.5% sodium chloride, 15% sorbitol, 2% propylene glycol, 5% glycine and 0.02% rosemary oleoresin in 72.48% water. Judging from water activity, thiobarbituric acid, viable cell count, volatile basic nitrogen, surface color and sensory evaluation, vacuum-packaging method in nylon/PE $(20{\mu}m/40{\mu}m)$ or polyester/viniliden chloride/polypropylene $(12{\mu}m/15{\mu}m/50{\mu}m)$ film bag did hardly damage to the quality of intermediate moisture products, but air-packaging method in polyethylene(0.06m/m) bag did considerable damage to the quality during storage for 60 days in an incubator with 49-51% relative humidity at $30^{\circ}C$.

• Food Science and Preservation
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• v.15 no.5
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• pp.719-724
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• 2008

The overall objectives of this study were to examine the potential of sturgeon as an intermediate moisture food (IMF) by measurement of nutritional components, such as minerals, fatty acids, amino acids, and water activity. Chemical compositions were as follows:moisture 73.2%, crude protein 19.9%, crude lipid 5.7%, ash 1.1%, and carbohydrate 0.1%. Minerals were K 317.70, P 259.88, and Mg 29.78 mg/100 g. Fatty acids detected were oleic acid (40.46% of total), palmitic acid (23.27%), and linoleic acid (15.35%). In addition, sturgeon was very rich in glutamic acid (1,189.71 mg/100 g) and deficient in serine (55.12 mg/100 g). Moisture content and water activity of sturgeon dried at $40^{\circ}C$ after soaking in different concentrationsof sugar and salt solutions were 15.12-16.24% and 0.68-0.79, respectively. Sensory evaluation of sturgeon soaked in different concentrations of sugar and salt solutions indicated that sturgeon soaked in 3.0% (w/v) sugar and salt solution scored highest.

• Korean Journal of Food Science and Technology
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• v.19 no.2
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• pp.113-118
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• 1987

An intermediate moisture model food system was used to investigate the effects of water activity (Aw), temperature, pH and polyethyleneglycol (PEG) on the Maillard reaction. The initial molar ratio of glucose to lysine was varied from one half to four. The maximum Maillard reaction was obtained from an initial glucose/lysine molar ratio of approximately three. The rate of Maillard reaction showed a maximum in the range of water activity of a normal intermediate moisture food. 'the model food system was prepared to hold water activity range of 0.47-0.84 and the samples were held at various temperatures. The maximum browning rate occurred at an Aw value of approximately 0.89 at $40^{\circ}C$ and $60^{\circ}C$, 0.74 at $30^{\circ}C$ and 0.67 at $20^{\circ}C$, respectively. The Arrhenius activiation energies for nonenzymatic browning pigment production were 18.03, 15.18 and 9.90 Kcal/mole for the sample with Aw 0.84, 0.74 and 0.67. When the pH of the model system was increased, a significant increase in the browning reaction was observed. On the inhibitive effects of PEG, the higher degree of polymerization, the more inhibition of browning reaction.

• Korean Journal of Food Science and Technology
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• v.21 no.3
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• pp.425-429
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• 1989

Functional relationships of carotenoid destruction and nonenzymatic browning during red pepper drying were established by the dynamic test using the moisture-temperature-quality history curve in actual drying experiments. The dependence of the rate constants on temperature and moisture content was established and analysed assuming that carotenoid destruction and nonenzymatic browning are the first order and the zero order reaction, respectively. Carotenoid destruction rate constant was high at high moisture and high temperature, and had a minimum value at some intermediate moisture content. As dependence of rate constant on temperature, activation energy of carotenoid decolorization ranged from 7.7 to 27.4 kcal/mol, showing higher value at higher moisture content. Nonenzymatic browning showed higher rate at higher temperature and higher moisture content. Activation energy of browning was in the range of 7.5-20.2 kcal/mol with higher value at higher moisture level.

• Food Science and Preservation
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• v.15 no.3
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• pp.340-346
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• 2008

This study investigated the microbial safety of apple snails and intermediate-moisture-content apple snail products subjected to various treatments, according counts of total bacteria, Escherichia coli, mold and yeast during storage at 4C Heating of raw apple snails at 95C for 5 min increased the storage period in relation to total bacteria, E. coli, mold and yeast-cell growth. Addition of 10% NaCl and 50% vinegar increased the microbial safety of apple snails. Microorganisms were not detected for 14 weeks in vacuum-packaged intermediate-moisture-content apple snail products stored at either 4C or 30C. These results suggest that heat treatment of raw apple snails, soaking in 10% NaCl and 50% vinegar solutions, and vacuum-packaging increases the shelf-life and microbial safety of apple snail products.

• Food Science and Preservation
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• v.14 no.3
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• pp.288-293
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• 2007

Intermediate moisture-apple snail products were prepared by adding glycerol, sorbitol, kiwi, or pineapple(2% or 5% w/w), as tenderizers, and by drying at $4^{\circ}C$ for 24 hr. The effects of the tenderizers on textural and sensory properties of the apple snail products at intermediate moisture levels were investigated. Moisture content and water activity of the products were ranged from 26.25 to 34.48% and from 0.83 to 0.87, respectively. The addition of glycerol significantly lowered water activity of apple snail samples compared to control prepared without tenderizers. On the other hand, significant increases in moisture content and water activity were observed in apple snail samples treated with kiwi or pineapple(p<0.05). All apple snail samples treated with tenderizers showed a lower shear force than did the control. Apple snail samples treated with 5%(v/v) glycerol showed a higher equilibrium moisture content than did the other samples. SDS-PAGE indicated that proteolytic enzymes in kiwi and pineapple clearly changed the structure of the myosin heavy chain and actin filaments of myofibrillar protein in apple snail samples. Intermediate moisture apple snail samples treated with tenderizers showed significantly improved overall sensory characteristics. The highest overall acceptability was obtained from apple snail samples treated with 5% pineapple, while the lowest overall acceptability was noted in the control sample. This study demonstrates that an acceptable apple snail, with intermediate moisture content, may be produced by using tenderizers at appropriate concentrations.

• Korean Journal of Food Science and Technology
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• v.4 no.4
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• pp.265-270
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• 1972

An attempt was made in this study to investigate the possibility of processing squid along with pork into an intermediate moisture food, as an acceptable new item in Korea. To obtain a palatable and low cost product, portions of mixture consisting of equal amounts of ground squid and pork were cooked in soy sauce for 20 min, soaked in glycerol for 20 min at $80^{\circ}C$, and then air dried for 90 min at $60^{\circ}C$. During storage for 42 days in saturated humidity incubator at $37^{\circ}C$, the total microbial counts of the products packaged in polyethylene (0.05 mm), polypropylene (0.05 mm) and plastic laminated aluminum foil were decreased from 230 per gram to 40, 20 and 10 per gram respectively. In another long range storage test of 6 months, the results paralleled the above trends. Even though the TBA value of the samples increased during the storage, it was not so serious as to damage on the organoleptic quality of this product. The results indicate that stored product was as acceptable as the freshly prepared one.

• Korean Journal of Food Science and Technology
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• v.20 no.5
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• pp.704-710
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• 1988

This study was, firstly, to investigate water holding capacity in terms of variation of moisture sorption isotherms of seasoned squid treated with sodium lactate, glycerol, propylene glycol, sorbitol, mannitol, sodium benzoate, potassium sorbate and calcium propionate, and secondly, the effect of humectant treatments on storage stability was studied. The criteria for storage stability was based on three quality factors, namely, lipid oxiations, color development by non-enzymatic browning reactions and lipid oxidation, and mold growth. The effect of humectants on equilibrium moisture content was in the following increasing order; mannitol < sorbitol < sodium lactate < propylene glycol < glycerol. The experimental data indicated that sodium lactate has, in practice, potentially positive effect on processing of seasoned squid. During the storage period of 60 days, TBA values increased in all samples tested as humectants concentrations increased up to 10%. However, in the range of 1-7% sodium lactate treatment, the degree of lipid oxidation, browning reactions and mild growth were not high enough to affect the quality of seasoned squid, when compared with conventionally manufactured ones.

• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.421-425
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• 1985

The changes of pectic substances during baking at $175{\sim}180^{\circ}C$ for 30 minutes and polygalacturonase activities of three sweet potato cultivars on textural properties were investigated. The three different types of sweet potato cultivars were the dry type (Wonki), the intermediate type (Shinmi), and the moist type (Chunmi). The moisture content, alcohol insoluble solid content, composition of pectic substances and hardness were determined before and after baking. It was found that HCl-soluble pectin was significantly changed into water soluble and sodium hexametaphosphate soluble pectin by baking. The dry type, Wonki showed the lowest moisture content, but the highest alcohol insoluble solid content and hardness. Wonki, whose polygalacturonase activity was the highest, had the highest HCl-soluble pectin content after backing.