• Food Science and Biotechnology
• /
• v.15 no.1
• /
• pp.152-157
• /
• 2006

Enterobacter sakazakii, designated as an unique microbial species in 1980, may cause bacteremia, necrotizing enterocolitis and infant meningitis. The distribution and the thermostability of E. sakazakii in unprocessed ready-to-eat (RTE) agricultural products of 252 and in 25 powdered infant formulas (PIF) were analyzed. Eighty one, 50, 43, and 47% of brown rice, pumpkin, potato, and carrot samples, respectively, had aerobic plate counts (ARC) in the range of 5 log CFU/g or more. Almost all the other products sampled had APC of approximately 2 log CFU/g. Fifty three, 75, 67, and 68% of banana, pumpkin, soybean, and carrot had Enterobacteriaceae counts approximating 3 log CFU/g. Sixty six percent of the brown rice tested had Enterobacteriaceae counts approximating 5-6 log CFU/g. E. sakazakii was isolated from 3/25(12%), 4/23(17%), 1/24(4%), and 1/27(4%) of PIF, brown rice, laver, and tomato samples, respectively. D-values were 3.52-4.79 min at 60 and $D_{60}-values$ were similar as the isolates reported. Thermal inactivation of four thermovariant E. sakazakii strains during the rehydration of PIF with hot water were investigated. At $50^{\circ}C$, the levels of E. sakazakii decreased one log CFU/g for 4-6 min and thereafter the levels remained stable for 20 min. At $60^{\circ}C$, inactivation by about 2 log CFU/g occurred for 20 min. Therefore, the unprocessed agricultural products might be a source of contamination for PIF when used as an ingredient after drying and pulverization. Rehydration of PIF for infant feeding with a water temperature of $60^{\circ}C$ rather than $50^{\circ}C$, as recommended by the manufacturers, may be helpful in the reduction of potential E. sakazakii risk.

• Korean Journal of Food Science and Technology
• /
• v.34 no.5
• /
• pp.799-804
• /
• 2002

Optimum conditions of freeze-dried carrots were determined using response surface methodology. Physicochemical and sensory properties of freeze-dried carrot prepared at different plate temperatures and chamber pressures were evaluated. Drying time increased with decreasing plate temperature and chamber pressure. Rehydration ratio decreased inversely with chamber pressure at low plate temperature, but increased proportionally with chamber pressure at high temperature. Density, color, and sensory off-flavor were not affected by the plate temperature and chamber pressure. Sensory color, tenderness, and carrot flavor increased with decreasing plate temperature, but were not affected by chamber pressure. Based on the drying time, rehydration ratio, and sensory attributes, optimum plate temperature and chamber pressure for the preparation of freeze-dried carrot were determined as $43^{\circ}C$ and 700 micronHg, respectively.

• Korean Journal of Food Science and Technology
• /
• v.33 no.2
• /
• pp.245-251
• /
• 2001

This research was conducted to study the changes in physical characteristics of mushrooms (Agaricus bisporus) as influenced by drying methods. Samples were dried using either hot air drying, vacuum drying, or freeze drying and changes in the color, browning index, hardness and rehydration rate were evaluated by response surface methodology. Hot air drying resulted in the fastest drying of sample as compared to other methods. The rate of drying was most affected by the environmental temperature rather than air velocity or vacuum pressure. The overall color difference increased as the temperature and air velocity increased. The overall color changes of the freeze dried samples were minimal as compared to those of fresh mushrooms. The hot air dried samples showed the greatest changes in the overall color, browning index as well as hardness. The freeze dried samples showed the best rehydration characteristic and maintained the best overall quality after drying.

• Food Science and Preservation
• /
• v.20 no.2
• /
• pp.284-288
• /
• 2013

Omija (Schizandra chinensis B.) slices were dehydrated with 20, 40, and 60% (w/w) red algae extract (RAE), and 40% of RAE was selected as the proper processing concentration considering the dehydration efficiency and cost of the dehydrating agent. The RAE-treated omija samples were compared with the hot-air dried samples in terms of the qualities such as the rehydration capacity and total phenolic contents. The rehydration ratios of the RAE-treated samples were greater than those of the hot-air dried samples by 31%. The total phenolic contents of the RAE-treated samples (1304.8 mg GAE/100 g) were higher than those of the hot-air dried samples (999.5 mg GAE/100 g). Therefore, omija slices can be dehydrated with RAE without quality loss.

• Food Science of Animal Resources
• /
• v.43 no.3
• /
• pp.428-440
• /
• 2023

Global meat consumption is increasing worldwide, however, supply remains lacking. Several alternative protein sources, such as cultured meat, plant-based protein production, and edible insects, have been proposed to overcome this shortage. Interestingly, edible insects are characterized by superior digestive and absorptive qualities that make them the ideal replacement for traditional protein production. This study aims to further the processing ability of insect protein by investigating the effects of various pre-treatment methods, such as blanching (HB), roasting (HR), and superheated steam (HS), on the nutritional properties and physicochemical characteristics of proteins extracted from Hermetia illucens larvae. The drying rate, pH value, color analysis, amino and fatty acid profile, as well as bulk density, shear force, and rehydration ratios of the above pre-treatment methods, were explored. HS was found to have the highest drying rate and pH value analysis showed that HB and HS samples have significantly higher values compared to the other modalities. Raw edible insects had the highest value in the sum of essential amino acid (EAA) and EAA index when compared to EAAs. HB and HS showed significantly lower bulk density results, and HS showed the highest shear force and the highest value in rehydration ratio, regardless of immersion time. Therefore, taking the above results together, it was found that blanching and superheated steam blanching pre-treatment were the most effective methods to improve the processing properties of H. illucens after hot-air drying.

• Preventive Nutrition and Food Science
• /
• v.16 no.2
• /
• pp.189-193
• /
• 2011

Kohlrabi (Brassica oleracea var. gongylodes L.) slices were dehydrated with maltodextrin (MD) at concentrations of 20, 30, and 40% (w/w), and the dried samples were compared with the freeze-dried and hot-air dried samples regarding various physicochemical qualities. The MD-treated samples had better results than those of freeze-dried or hot-air dried samples in terms of rehydration ratio and color. The total phenolic content of the MD-treated sample was similar to that of the freeze-dried and higher than that of hot-air dried sample. The ascorbic acid content of the MD-treated samples was also higher than that of the hot-air dried one. These results suggest that kohlrabi can be dehydrated with MD instead of hot air.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1996.04a
• /
• pp.283-283
• /
• 1996

The hydrolyzed-lactose milk for the lactase-deficient subject is sweeter than whole milk, and some subjects dislike its taste. To overcome this shortcoming the dried liposomes containing ${\beta}$-galactosidase to digest lactose in milk after drinking were prepared and examined the possible application of this dried liposomes to the lactase-deficient subjects. To improve the stability of conventional liposome suspension, the dried liposomes in the presence of trehalose were prepared by the dehydration-rehydration vesicles method. Small unilamellar vesicles, prepared with egg phosphatidyl cholesterol, and cholesterol, were mixed with ${\beta}$-galactosidase solution and then ;up[jo;ozed. The freeze-dried liposome was rehydrated and centrifuged. The resultant multilamellar vesicles were mixed with trehalose(4g/g lipid) and then lyophilized to produce final dried liposome. Trehalose increased the entrapping efficiency of liposomes by 3 fo1d compared to the liposomes without trehalose (13% vs. 46%).

• Food Science and Preservation
• /
• v.5 no.3
• /
• pp.305-314
• /
• 1998

In the drying process, many undesirable physicochemical changes occur that influence dried food product qualities. Pretreatments method is used to reduce the deterioration of dried food product qualities such as color, flavor, texture, rehydration ability and retention of nutrients. The methods of pretreatments are blanching, chemical treatment and osmotic dehydration. Osmotic dehydration is a water removal process which is based on placing foods in a concentrated osmotic solution or in a dry osmotic material. A large number of process variables have a significant effect on process and final product quality. In order to improve final product quality it is necessary to know the role of each process variable and understand the mecanisms throughout the process. Osmotic dehydration is a valuable processing tool with great future in minimal processing of fruits and vegetables.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.12 no.sup1
• /
• pp.93-97
• /
• 2009

Worldwide, diarrhea remains one of the most common illnesses among children. Oral rehydration therapy (ORT) is the cornerstone of diarrhea treatment. Yet, the rates at which ORT is used are still disappointingly low. Additional treatment interventions include antimotility drugs, antisecretary drugs, adsorbents, probiotics, antibiotics, oral immunoglobulin, micronutrient supplementation. Drugs are generally not necessary. However, selected probiotics may reduce the duration and intensity of diarrhea. Zinc is beneficial especially to malnourished children with diarrhea. Antibiotic treatment is effective mainly in shigella and cholera infection. Other drugs may be effective but require further investigations.

• The Korean Journal of Food And Nutrition
• /
• v.23 no.1
• /
• pp.114-117
• /
• 2010

The effects of isolated soy protein(ISP) content on the physicochemical properties of extrudates from rice flour produced by a single-screw extruder were evaluated. The integrity index(II), nitrogen solubility index(NSI), rehydration ratio(RR), and density were measured as indices of the changes of physicochemical properties of rice extrudates. Increased amounts of ISP resulted in increased II but decreased RR and density. There was no change in the NSI value. It was concluded that the addition of ISP to the raw material could be helpful in texturization of rice extrudate.