In this study, spray-dried double emulsion loaded bromelain was applied to Japanese Spanish mackerel fillets to develop fish-type, elderly-friendly foods. Japanese Spanish mackerel, treated with spray-dried double emulsions, were stored at 4oC for 24 h. For the characterization of emulsion particles, the particle size, ζ-potential, and morphology were determined. The color, TBARS, VBN, TMA, hardness, and adhesiveness of fish fillets treated by emulsion were measured for physicochemical properties. All the particle sizes of spray-dried emulsion were decreased while their double emulsion structure was maintained. Spray-dried emulsion reduced the color difference of fish fillets and did not catalyze lipid oxidation and protein decomposition. Values of TBA, VBN, and TMA of all fish did not exceed 0.5 mg MDA/kg, 30 mg/100 g, and 10 mg/100 g, respectively, which are considered edible limits regardless of bromelain or emulsion application. Bromelain modified fish fillets' hardness and adhesiveness to be suitable for elderly food, although it was encapsulated in the emulsion. Thus, spray-dried fish oil W/O/W double emulsion-loaded bromelain can be applied as a fish tenderizer, and this study’s results can be utilized to develop elderly-friendly food.
본 연구에서는 vitamin C를 넣어 발효시킨 오징어 액젓을 조미용도로 활용하기 위해 발효 과정 중 아미노산함량 변화, 염도별 이화학적 특성, 오징어 액젓과 시판 저염간장 과의 관계양상을 파악하였다. 발효 중 총 아미노산은 증가 하였으며, 그중 Asp, Pro, Gly, Ala, Val, Ile, Leu의 함량은 발효 기간에 따라 증가하였다. 소금 첨가량에 따라 오징어 액젓의 염도와 당도는 증가하였으며, 수분과 pH는 감소하는 것으로 나타났다. 색도의 경우 소금을 넣을 경우 명도, 적색도, 황색도 모두 감소하였고, 소금 첨가량에 따른 차이는 있으나 특별한 경향을 보이지는 않았다. 동일한 염도의 오징어 액젓과 시판 저염간장의 관능검사 결과, 색은 모든 염도에서 차이를 보였으며, 향은 1, 2, 4%에서 차이를 보 였다. 짠맛은 염도가 높아질수록 기호도가 높아지는 경향 을 보였다. 오징어 액젓의 단맛은 가장 낮았으며, 신맛은 가장 높은 기호도를 가졌다. 오징어 액젓과 저염간장의 기 호도 양상은 83.84~94.51%의 설명력을 가지며, 향과 색의 기호도는 저염간장보다 오징어 액젓이 높았고, 감칠맛은 반대로 저염간장이 높은 것으로 나타났다. 또한 감칠맛과 단맛은 전반적 기호도와 양의 상관관계를 가지는 것으로 조사되었다. 오징어 액젓의 염도가 높아질수록 저염간장군과 가까워지는 것으로 나타나 일정 염도를 가질 때 간장과 유사한 용도로 사용이 가능할 것으로 보인다.
This study was performed to analyze a saltiness enhancement at the same salt content through multiple emulsion. We compared the samples with different conditions to determine the optimum stability conditions of water-in-oil through layer separation rate, microscopic observation and size analysis. Four electrolytes such as NaCl, KCl, MgCl2, and CaCl2 were used and agar contents ranged from 0 to 1% were experimented at different volume ratios including 5:5, 4:6, 3:7, 2:8, and 1:9 of water and oil. As a result of this study, the droplet size according to the electrolyte type did not show significant differences (p<0.05). Therefore, KCl was used to facilitate in-body excretion of NaCl in the outer water phase, and corn oil containing 8%(w/w) polyglycerol polyricinoleate was used as oil phase. When the volume ratio of water and oil was 3:7, 2:8, and 1:9, the layer separation rate was relatively slow and droplet size was also small. It reveals that the particle size becomes smaller as the water volume ratio decreases. However, considering the amount of water to be stored and eluted on the inner water, appropriate volume ratio of water and oil should be adopted to 3: 7. At Microscopic observation depending on agar concentrations, small particle size appeared at 0.2% and 0.4% agars. When the water and oil ratio was fixed at 3:7, the particle size was measured at 0.2% and 0.4% agar using a zeta sizer. In conclusion, the droplet size of 0.2% agar was smaller than 0.4%. Therefore, the most stable water-in-oil emulsion was obtained with 0.2% agar, when water to oil ratio was 3:7.
Probiotics are defined as advantageous microorganisms to human when they are ingested. However, without any protection, the viability of microbes and their adhesive ability to surface of colon decreases through acidic condition such as stomach and intestines. Therefore, many studies have been conducted to figure out to enhance not only the viability of probiotics, but also its adhesion for increasing effect of probiotics. In this study, extrusion method was conducted to encapsulate Enterococcus faecium. E. faecium-alginate solution was injected to CaCl2 solution with regular side air injection. To prevent coagulation of beads, stirring was conducted in CaCl2 solution and encapsulated alginate-Ca2+ microspheres were produced. For optimal encapsulation condition, air pressure was 100 mbar, flow rate of E. faecium solution was 0.02 ml/h and stirring rate was 200 rpm. For mucoadhesive ability, Monolayer of HT-29 cells used as a colon cell and encapsulated cells were inoculated and incubated in 37℃, 5% CO2/95% air atmosphere for 1 h. Encapsulation efficiency of the encapsulation method used in this study was 98.2%. For mucoadhesive test, the concentration of inoculated E. faecium was 9.9×108 CFU/ml and the concentration of adhered E. faecium was 1.6×106 CFU/ml. In conclusion, encapsulation efficiency of extrusion method was high enough to be accepted for this study, however, alginate-Ca2+ microspheres revealed lower adhesive ability compared to expectation. Therefore, it needs further studies to increase adhesive ability with other polymers.
In this study, we investigated the change of physical properties associated with the temperature of vegetable mixed oil and fat in order to produce vegetable oil and fat suitable for plant meat production. The canola oil and coconut oil were mixed at various weight ratios, and the phase change temperatures by the ratio of two oils were measured using the differential scanning calorimetry (DSC). Storage modulus (G'), loss modulus (G") and viscosity were measured using a rheometer at 20-40°C and 0.4 Hz-100 Hz. Storage modulus (G') at constant frequency (10 Hz) was measured in a continuous section of 10-50°C. As the coconut oil content increased, the peak of the melting point moved to the lower side. The viscosity was higher in order of canola oil, mixed oil, and coconut oil, and the viscosity showed a tendency to decrease as the temperature increased. In the liquid state, it showed a tendency to increase after the value of storage modulus (G') and loss modulus (G") decreased from 0.634 Hz-1 Hz. The conversion time point of storage modulus (G') of continuous temperature change is consistent with the melting point temperature of DSC, as the passed start at 10°C, storage modulus (G') increased with an exception of canola oil. Using these results, we will pursue to produce a mixed plant oil applicable to the production of vegetable meat.
Salt is generally used for food seasonings and preservations as a common ingredient. However, excess salt intake has generated health issues such as high blood pressure, osteoporosis, stroke, and heart diseases. Recently, desires and interests of low-salt cooking have been increased among people who want healthy diets. The aim of study was to compare the physicochemical characteristics of a fermented squid sauce added with vitamin C and commercial low-salt soy sauces. Thawed and crushed squids were fermented until the solid squid became liquid at 25°C with an addition of 5% (g/g) vitamin C. Then, fermented squid sauce was heated at 100°C for 30 min and filtered. All samples were measured in multiple aspects of amino acid nitrogen, salt, sugar and water content, pH, chromaticity and brown color, and sensory test. In the results, color values showed no significantly difference between all the samples (p>0.05). Water content value of the fermented squid sauce was the highest among samples. Brown color, salt contents and sugar contents of the fermented squid sauce were significantly different than other low salt soy sauces with an exception of the sauce made with functional salt. These results showed a similar tendency as those of sensory evaluation. As conclusion, the possibility of fermented squid sauce added with vitamin C showed a possibility as a candidate of low-salt soy sauce.
The red ginseng is known to have effects on antioxidativity and cytotoxicity. Nanoscale active substances have various advantages such as improved bioavailability and permeation ability into the cell. However, few studies conducted with the nanoparticles of red ginseng due to its low yield rate and difficulty of manufacturing the product in pilot scale. This study, therefore, investigated the size effects of ultra-fine powder of red ginseng on antioxidativity and cytotoxicity. Red ginseng powder (6, 8, or 158 μm) prepared using a pilot scale was provided by a local company. Antioxidativity was measured by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assays, and cytotoxicity was tested by methylthiazolyl tetrazolium (MTT) assay. The results of DPPH and ABTS radical electron donating ability IC50 of red ginseng were ranged from 2.27 to 3.34 mg/ml and 2.94 to 3.09 mg/ml, respectively, which were not significantly different between all samples. However, the results of cytotoxicity clearly showed a pattern of decreased toxicity in 6 and 8 μm power compared to 158 μm powder. Unexpectedly, particle sizes of red ginseng did not significantly affect antioxidativity. It is believed that these were related to the process of pilot scale production. These phenomena are also believed to be caused by aggregation of low size power particle that increases water holding capacity. From our result, it is concluded that this range of particle size of red ginseng affected the reduction of cytotoxicity.
Soybean peptide (SP) exhibited low intestinal absorption at oral administration due to its fragile structure under gastric digestion. Therefore, we have attempted to encapsulate peptide by cross-linkage interaction between positive charged chitosan (CS) or chitosan oligosaccharide (CSO) and negative charged peptide. The CS (or CSO) with SP nanoparticles were prepared by using ultrasonification technique. The objective of this study was to find the optimal processing method by changing concentration, pH, and homogenizing conditions. We measured physicochemical properties such as particle size, zeta-potential, encapsulation efficiency (EE%), release rate (RR) and antioxidant ability of samples. The results showed that the optimal processing method was using 0.5% (w/v) CSO (diluted by pH 3 Acetic acid buffer) mixed with 0.5% (w/v) SP (diluted by pH 6 buffer) by 9:1 ratio. Afterwards, using high-speed mixer at 12,000 rpm for 3 min, and then passed 2 times through an ultrasonicator (50% power, 3 min). In this way for processing, the particle sizes of CSO/SP nanoparticles were approximately 300 nm, zeta-potential were approximately 45 mV. In addition, the EE% and RR of CS/SP nanoparticles was higher than the CSO/SP nanoparticles. The increase in antioxidant ability of SP was attributed to the affected by CS/CSO microcapsules. In conclusion, this research can befoundation for the manufacturing process of CS/SP nanoparticles, and it was expected that the future application of this nanoparticle in food matrix.
Cryoprotectant is a substance used to protect biological tissue from freezing injury. However, there was few research paper on application of cryoprotectant in food stuff although its benefits was approved from the biological cell tissues. The objective of this study was to investigate the effect of the sugar addition as a cryoprotectant on the properties of frozen soybean sprouts. Before freezing process, the samples were blanched at 100°C for 1 min to observe the influence of blanching treatment. The blanched or non-blanched soybean sprouts was immersed in sugar solution as cryoprotectant, and continuously, the samples were frozen at -18°C for 24 h. Their physicochemical properties such as drip loss, hardness, color and cellular tissue were analyzed after thawing in running water. In our study, the drip loss of blanched sample without sugar was 43%, and comparatively, blanched one with sugar was 20% which was the lowest value among all samples. There was no significant difference of hardness between sample with sugar and without sugar. From our results, it was supposed that sugar can protect the soybean sprouts during freezing process regardless blanching process.
Excessive salt intake in body induces health risks resulting high blood pressure or heart diseases. Therefore, the low salt concentration and sale tasted food is needed by means of the modification of manufacturing process. The purpose of this study was to study the effect of inhomogeneous salt localization in bread to enhance the saltiness encapsulated salt. The 0, 0.5, 1, 1.5, and 2.0% of liposome encapsulated salt (LS) was added into the baking of white pan bread. The final salt concentration was adjusted at 2% by addition of salt. After baking the bread, the moisture content, loaf volume, fermentation rate, color, texture analysis, salt release rate and sensory test were measured. From this study, moisture content has no significant difference between control and treatments (p>0.05), except for 2.0% LS. Lightness of all treatments was higher than control (p<0.05), whereas, there were no significant difference in hardness (p>0.05). From the sensory test, the bread added 2.0% LS was showed the highest value from the salty taste. Moreover, it is related to the highest release rate of salt was represented at 2.0% LS. In conclusion, the salty intensity of bread can be enhanced by the salt localization using encapsulation of salt.
Recently, semi-dried sweet potato is popular as a natural snake for children’s dessert. The drying condition was optimized to obtain high quality of sweet potato by oven drying process. The mashed yellow and chestnut sweet potato was dried using the oven drier at different temperature (50, 60, 70, and 80°C) then evaluated for the moisture content, appearance observation, texture properties, and sugar contents and sensory test in every 2, 6 and 12 hours. During the dehydration and drying process, the ending point of moisture content divided in three zone from 0-2 hour, 4-6 hour and 8-12 hour. The moisture content was dramatically decreased from 0 hour - 8 hour, but after 8 hour there is no significant decrease. Yellow sweet potato dried at 80°C for 6 hours was investigated as good product base on the sensory test, hardness value, and color appearances as compared to chestnut potato.
In this study, we investigated the effects of different pre-treatment conditions such as blanching and drying process to improve its quality. Bracken samples were treated by drying (70°C for 40 min), blanching (100°C for 2 min) or mixed (blanched and dried [BD]), respectively. These treated samples were analyzed for their physicochemical properties such as pH, color and microbial growth. The pH of bracken increased from 6.6 to above 6.9 through all treatment. From color observation, the L* and b* values increased after drying process, whereas, the a* values decreased. Water contents of bracken decreased by about 80% from 93% through drying process. After samples treated by pre-treatments, hardness increased, especially after drying process. For the microbial study, raw bracken had 5.6 log CFU/g of aerobic bacteria and 2.8 log CFU/g of total coliform. Blanched and BD samples had about 2 log CFU/g of aerobic bacteria and 1.8 log CFU/g of total coliform, acceptable for food. From our results, it is concluded that the properties of blanched samples had similar to raw samples to guarantee for microbial safety. From the obtained results, the blanching process without drying process is necessary to apply freezing process as pretreatments.
In the food industry, freezing storage has been an important process for maintaining the properties of food materials. In order to maintain the quality of blanched Colocasia esculenta (L.), Schott stem, packaging, freezing, and thawing methods were optimized by determinations of the physicochemical properties. For the comparison of packaging method, Colocasia esculenta (L.) Schott stem packed by air containment had the lowest significant differences of properties such as hardness and drip loss compared to the control samples. Overall, the drip loss of Colocasia esculenta (L.) Schott stem had lower value at fast freezing rate (immersion freezing). Considering the result of the drip loss, high frequency thawing was more effective than other thawing methods. Therefore, it was supposed that samples treated by air-containing packaging, immersion freezing, and high frequency thawing used the optimal method to maintain the original quality of Colocasia esculenta (L.) Schott stem.
Food freezing preservation is an important process due to its high quality and long shelf-life. In order to improve the quality of frozen sweet potato stem, the freezing rate, thawing, and packaging method was optimized by the determination of physical properties. There was no significant difference among the treatment of freezing rate. Further, the drip loss of sweet potato stem was higher at a relatively fast freezing rate (immersion freezing) than at slow freezing rate (natural convection freezing at -20 or -40oC). For the comparison of packaging methods, the aircontaining packaged sweet potato stem had the lowest significant differences from the result of color, pH, and hardness. From the result of the drip loss, the high frequency and microwave using thawing samples were more effective than room temperature and water thawing. Therefore, fast freezing and thawing rate with air-containing package were recommended to obtain the better quality of sweet potato stem.
Blanching and freezing of beef are important techniques used in developing frozen home meal replacement (HMR) products. These pre-thermal treatments minimize the deterioration of beef during storage. Beefs are washed, defatted, sliced (5.0×0.5×0.5 cm, fiber direction), and blanched by immersion in hot water for 2 min. Thereafter, the blanched beefs are spin-dried and frozen by individual quick freezing (IQF) method. Finally, the frozen beefs are packed using two methods: vacuum packages and air-containing packages. Packed beefs are stored at -12oC, -18oC, and -24oC for nine months. One in every three months, they are thawed in a microwave (400W). While thawing, vacuum-packed samples possess lower thawing loss than air-containing-packed ones. Compared to raw beef, blanched beef have a higher L* and lower a* value. However, less changes are observed after blanching the beefs as the enzymes get inactivated in the blanching process. Shear force of beef also increase through blanching. Moreover, vacuum-packed samples have maintained their hardness to a greater extent than the air-containing-packed samples. All the samples have met microbial safety standards. Thus, it is inferred that vacuum-packaging and -18oC storage temperatures are the best condition for maintaining beef that is later developed into HMR product.