Heavy metals are typical contaminant in water and need to be removed because they are non-biodegradable and can accumulate in human body. To remove metal and other contaminants from water, chemical absorbents are widely used due to their low cost. Herein, hybrid materials comprised of amylose and single wall carbon-nanotube (swCNT) was developed as the absorbent for water purification. A high adsorption properties of carbon-nanotubes have been utilized in designing effective absorbent but its poor dispersity in water is a limiting factor for practical use. Single wall carbon-nanotube was hybridized with amylose chain produced by enzyme reaction of amylosucrase and their tendency to self-assemble in aqueous environment. The amylose-swCNT microparticles were characterized by FE-SEM and turned out to be spherical structure with CNTs embedded throughout the amylose matrix. The ability of amylose-CNT microparticles to remove copper was examined. Concentration of copper was decreased after reaction with amylose-swCNT microparticles. Although amount of decreasing copper was less than swCNT on same total mass, Adsorption efficiency of amylose-swCNT microparticles was good because their swCNT content was only 10% of total mass.
Recently, there is a growing interest of consumers in natural products thus a large number of natural preservatives have been studied as food additives. Among those natural preservatives, rosemary extract are commonly used by the food industry to extend the shelf life of several products. Nevertheless, the incorporation of the rosemary extract in food matrix is highly limited due to the low water solubility and poor chemical stability of constituents of rosemary extract. In this context, it is needed to find a way that can improve the water solubility to incorporate rosemary extract into aqueous system like foods. Hence, in this study we added surfactants that have a relatively high hydrophilic-liphophilic balance number into rosemary extract solution to increase the water solubility of rosemary extract and then investigated the microbial activities of rosemary extract with surfactants. Tween 20, decaglycerol monooleate, decaglycerol laurate and decaglycerol myristate were used in a range 0.1~4% and rosemary-surfactant solution was prepared by dissolving rosemary in surfactant added phosphate buffer (pH 7) as much as extract can be dissolved. Water solubility of rosemary-surfactant solution were examined by observance of the UV-vis spectra. The antimicrobial effects rosemary-surfactant solution on B.subtilis were also examined by paper disc diffusion method. Rosemary extract showed poor solubility in normal phosphate buffer but its water solubility was highly increased when surfactant was added. This tendency was lasted at all types of surfactant. This is because of amphipathic property of surfactant. Antimicrobial effect to B.subtilis was observed when a relatively lower concentration of surfactants were used, however, not in high concentrations. This result might be attributed to the formation of surfactant micelles containing rosemary extract when a relatively higher concentration of surfactants were used. The information presented may be useful for the development of a new rosemary-loaded delivery systems.
Quality changes of carrots thermally processed in a large size (5 kg) retort pouch during 52 weeks of storage period were investigated upon different packaging methods and package shapes. To improve the efficiency of thermal processing (121.1°C, 0.15 MPa), the carrot (i.e., solid) and the broth (i.e., liquid) of carrot soup were separately packed and sterilized. The quality changes of carrot packed without liquid were compared with those with liquid. Two different package shapes such as rectangular parallelepiped and cube were also evaluate to figure out the efficiency of the heat penetration rate for the large size of pouch. The location of cold points and the total thermal processing time (TTT) were different upon the treatment. Fo-values, satisfying the TTT to at least 6 min, were 27, 54, and 114 min from the rectangular parallelepiped, cube and solid/liquid mixed group, respectively. In the mixed groups, the hardness and chewiness of solids (carrot) was significantly smaller than that measured in the other groups as TTT increased. Carrots treated in the rectangular parallelepiped shape showed a significantly higher texture than the cube shape for both immediately after the thermal treatment and during the storage period. Coefficient of variation (CV), which indicates the quality variation within the same treatment, of texture properties obtained from the outside and the center of the sample were compared to evaluate the quality variation within the same treatment. The CV of hardness and chewiness of the rectangular parallelepiped and the cube shape were calculated 7.56 and 47.19, and 29.16 and 65.28, respectively. This demonstrated that more uniform quality could be expected from the thermal treatment in the rectangular parallelepiped shape
Raman Spectroscopy is a non-destructive analysis method without complex pre-processing and it can reduce the costs and time. A surface-enhanced Raman scattering (SERS) technique was tried to the detection of Benzo[a]pyrene which is one of the hazardous minor components of foods. To demonstrate the Raman signal enhancement effect by graphene as substrate, thymine was used as the standard material. As a result, the Raman signal of thymine has 102 enhancement. Herein, new SERS trials established to pursue improve the speed, simplicity and suitability of detecting minor components in foods.
Various methods for the detection of E. coli O157:H7 in food have been developed in the past decades. However, current detection methods require specialized instruments and lengthy preparation time. In an effort to achieve a rapid and sensitive detection, we developed a radial chromatography (RC) biosensor integrated with gold nanoparticle (AuNP) conjugated with antibody for the detection of E. coli O157:H7. The immuno-AuNP binds to E. coli O157:H7 creating AuNP-E. coli O157:H7 complexes by specific antigen-antibody interaction. The AuNP-E. coli O157:H7 complexes can be identified clearly from free AuNP by RC based on their mobility on porous matrix. Thus, the AuNP complexed with target bacteria, E. coli O157:H7 could be discriminated from free AuNP by radial chromatography. The results showed that the developed RC biosensor is highly selective to E. coli O157:H7 over non-target bacteria, including Bacillus cereus, Staphylococcus aureus and Vibrio cholerae with a detection limit of 105 CFU/ml. When combined with a pre-concentration step using immunomagnetic beads, we could further enhance the detection limit down to 103 CFU/ml. In this study, we developed a novel method that is rapid, sensitive and applicable for qualitative and quantitative detection of E. coli O157:H7. The detection procedure is simple and the results can be easily determined by naked eyes, suggesting that this system is practical and can be applied to the field diagnosis in food industry for the detection of pathogenic bacteria.
원강(흙을 제거하지 않은 생강)은 수확 후 출하까지 주로 토굴저장을 하고 있으나, 원강의 부패율이 저장 후 5개월 내에 10~50%로 상당히 높고, 출하시기의 선택과 작업상의 번거로움 등의 현장애로사항을 나타내고 있다. 본 연구는 열풍건조에 의한 생강의 건조시간과 생강분말의 영양성분과 항산화력에 대한 생강편 두께의 영향을 조사하였다. 생강 원료는 2015년 11월경 경상북도 영주지역에서 수확하여 13~15°C와 98~100%RH 의 저장고에서 저장된 원강을 2016년 6월경에 구입하였다. 원강은 브러쉬를 이용하여 흐르는 물에서 흙을 제거하여 부패 및 목질화된 부분을 제거한 후 2, 5, 8 mm 두께의 생강편으로 성형하였다. 준비된 생강편들은 중량변화 연속측정용 건조모듈이 장착된 열풍건조기를 이용하여 55°C에서 건조하면서 건조시간을 결정하였다. 영양성분 및 항산화력 분석을 위해 55°C에서 결정된 건조시 간에 따라 건조한 후 100 mesh 선별체망이 장착된 콜로이드밀을 이용하여 분쇄하여 생강분말을 제조하였다. 열풍건조 의 대조군으로 동결건조법을 사용하였다. 제조된 생강분말들은 일반성분(수분, 조단백, 조지방, 조회분, 탄수화물), 지 표성분(6-gingerol 및 6-shogaol), 색도, 갈변도 및 항산화력을 분석하였다. 생강편의 두께가 작아질수록 건조속도는 빨 라졌으며, 건강의 수분함량을 6%로 할 때 2 mm 생강편은 5시간, 5 mm는 7시간, 8 mm는 11시간이 소요되었다. 생강 편 두께에 따라 일반성분은 유의적인 차이를 나타내지 않았다. 6-gingerol과 6-shorgaol에 있어 2 mm와 5 mm 시료들 사이에서는 큰 차이를 나타내지 않았으나 8 mm 시료에서 감소하였고, 열풍건조 시료들 모두 동결건조 시료보다 높은 함량을 나타내었다. 색도와 갈변도는 동결건조 시료와 유의적인 차이를 나타내었으나, 동결건조와 열풍건조 사이의 수치상의 큰 차이는 관찰되지 않았다. 항산화력은 열풍건조 시료가 동결건조의 것보다 높은 수준을 나타내었다. 따라 서 건조생강을 제조할 경우 동결건조보다는 열풍건조가 더 효과적인 방법인 것으로 생각된다.
생전분과 검류의 혼합물은 화학적 변성전분의 물리적 기능성을 부분적으로 대체할 수 있는 것으로 보고되고 있다. 본 연구는 생전분과 음이온성 검 혼합물 페이스트의 유변학적 특성에 대한 건열처리의 효과를 탐색하였다. 전분원료 로 감자전분, 고구마전분, 찹쌀전분 및 멥쌀전분을, 음이온성 검류는 carboxymethylcellulose (CMC), low-methoxy pectin (LMP), sodium alginate (NAG), λ-carrageenan (λCG) 과 xanthan gum (XAT)를 사용하였다. 음이온성 검들은 1% (w/w) 용액으로 제조하고 pH 5.5 (NAG)로 조정하여 전분과 혼합한 후 50°C에서 건조하여 전분-음이온성 검 혼합물을 제조 하였다. 전분과 음이온성 검의 혼합율은 건조중량 대비 99:1 이었다. 전분-음이온성 검 혼합물은 130°C의 컨백션오븐 에서 4시간 동안 건열 처리하였다. 건열처리 전후의 전분-음이온성 검 혼합물들은 페이스팅 점도 특성과 점탄특성을 조사하였다. 주어진 음이온성 검에 있어 전분-음이온성 검 혼합물들의 페이스팅 점도 특성은 점도 수준에 있어 차이는 있었으나 각각의 전분원료들이 보유한 고유의 페이스팅 점도특성들의 차이와 유사한 경향을 나타내었다. 감자전분과 고구마전분의 경우에 있어 건열처리 여부에 관계없이 생전분의 페이스팅 점도보다 낮은 수준을 나타내었으며, 건열처 리된 전분-음이온성 검 혼합물들은 무처리 혼합물들보다 낮은 수준을 나타내었다. 전분-음이온성 검 혼합물 페이스트 의 점탄특성은 혼합물들의 페이스팅 점도특성의 최종점도의 경향과 유사하였다. 전반적인 결과들을 종합할 때, 감자 및 고구마전분에 있어 음이온성 검류의 첨가와 이들 혼합물의 건열처리는 적합하지 않았다.
국내의 베리류는 대부분 딸기가 주종으로 여겨지다 해외에서 생산된 베리류의 국내수입으로 인해 다양한 종류의 베리 류가 시중에 판매되어 왔고, 최근 국내에서는 다양한 베리류의 재배가 이루어지고 있다. 베리류는 anthocyanins, flavonoids, phenolic acids 등 다양한 polyphenolic compound와 vitamin C와 E 등을 다량 함유하여 기능성 제품개발 원료로 각광받고 있 다. 또한 베리류 특유의 향과 맛, 색으로 인해 음료의 중간소재로써 많이 사용되고 있다. 그 중 기능성 성분 함량이 높고 대중적으로 잘 알려진 블루베리와 아로니아를 시료로 선택하여 기능성 성분 분석을 실시하였다. 시중에서 판매되고 있는 국내산 블루베리와 아로니아를 제공받아 증류수(물)과 20, 40, 60, 80, 100% methanol (MeOH)로 각각 추출 후, 추출물의 Total phenolics contents(TP), total flavonoids contents(TF), total anthocyanins contents(TA)를 측정하였다. 추출물의 항산화능 을 측정하기 위해 ABTS radical 소거능 및 DPPH radical 소거능을 측정하였다. 그 결과, TP는 블루베리의 경우 127±2-165±1 mg GAE/100g sample으로 나타났고, 60% MeOH 추출물이 가장 높았으며, 아로니아의 경우 452±12-991±15 mg GAE/100g sample로 나타났으며, 40% MeOH 추출물이 가장 높았다. TF는 블루베리의 경우 34±5-61±4 mg CE/100g sample, 아로니아 의 경우 195±24-382±13 mg CE/100g sample 측정되었으며, 각각 60% MeOH과 40% MeOH 추출물에서 가장 높게 나타났다. TA는 블루베리의 경우 81±2-92±11 mg CGE/100g sample, 아로니아의 경우 274±11-462±35 mg CGE/100g sample로 측정되 었으며, 각각 60% MeOH, 40% MeOH 추출물에서 가장 높게 나타났다. 베리류의 항산화능 측정 시, ABTS 라디컬 소거능 은 블루베리의 경우 159±11-206±7 mg VCE/100g sample, 아로니아의 경우 506±125-1,487±162 mg VCE/100g sample로 측정 되었으며, 각각 물 추출물과 60% MeOH 추출물에서 가장 높게 나타났다. DPPH 라디컬 소거능은 블루베리의 경우 116±2-153±5 mg VCE/100g sample, 아로니아의 경우 621±21-1,025±14 mg VCE/100g sample로 나타났고, 각각 60% MeOH, 40% MeOH 추출물에서 가장 높게 측정되었다. 베리류는 TP, TF, TA 및 항산화능을 모두 고려하였을 때, 40·60% MeOH 추출조건에서 기능성 성분 함량 및 항산화능이 가장 높은 것으로 나타났다.
카나우바 왁스(carnauba wax)에 자몽종자추출물(grapefruit seed extract, GSE)과 오리가노 방향유를 혼합하여 코팅제를 개 발하였고, 개발된 코팅제를 감귤(Citrus unshiu Marc.)에 코팅하여 코팅의 Penicillium italicum (P. italicum) 발생 억제와 감귤 의 저장성 증대에 대한 효과를 연구하였다. 카나우바 왁스에 0.5, 0.8, 1.0%(w/w)의 GSE와 Tween-80 (25% w/GSE w)을 혼 합한 후 10,000 rpm에서 2분간 균질화하여 코팅액을 제조하였다. 제조된 코팅액의 유화안정성과 분산안정성은 각각 입자 크기와 제타전위 그리고 후방산란으로 측정되었다. 코팅되지 않은 감귤과 GSE를 1% 혼입한 카나우바 왁스(GSE-carnauba wax) 코팅액으로 코팅된 감귤은 4°C와 25°C에서 각각 28일과 7일간 저장되었고, 저장 기간 중 이화학적 특성과 P. italicum 의 생장을 관찰하였다. GSE-carnauba wax 코팅액의 입자크기와 제타전위는 다른 코팅액에 비해 유의적으로 각각 작고 높 았으며(p>0.05), 후방산란은 저장 기간이 증대하여도 상대적으로 유지되었다. 25°C에서 저장된 GSE-carnauba wax 코팅액이 P. italicum 생장을 가장 효과적으로 억제하였다(p<0.05). 또한, GSE-carnauba wax 코팅액으로 코팅 처리하여 4°C에서 저장 된 감귤의 중량감소율, CO2 발생량, 경도 감소율은 코팅 처리하지 않은 감귤보다 낮은 것으로 관찰되었다(p<0.05). GSE-carnauba wax 코팅은 저장 중의 저장온도와 관계없이 감귤 껍질의 색도에 영향을 미치지 않았다(p>0.05). 감귤의 당도, 적정 산도 및 pH는 코팅 여부, 코팅액 내 GSE 첨가 여부, 저장 온도 그리고 저장 일수에 영향을 받지 않았다(p<0.05). 저장 일수가 길어질수록 25°C에서 저장된 감귤의 총 폴리페놀 함량, 항산화능은 코팅 여부와 관계없이 감소하기 시작했고 (p<0.05), 아스코브산 농도는 코팅처리 된 감귤에서 더 높았다. 본 연구에서 개발된 GSE-carnauba wax 코팅은 감귤의 P. italicum 생장과 저장 중 품질 저하를 억제하여 감귤의 저장 기간을 효과적으로 연장시킬 수 있을 것이다.
백년초 분말과 백년초 추출물의 항산화능과 친수성에 대한 아르곤 콜드 플라즈마(cold plasma, CP) 처리의 영향을 연구하였고, 두 특성에 대한 최적 CP 처리 조건을 결정하였다. 백년초 추출물 시료는 백년초 분말을 80% 에틸알코올 로 추출한 후 감압 농축하고 동결건조하여 얻었다. CP 처리 조건은 플라즈마 형성 전력(600-900 W)과 처리 시간 (10-40 min)을 변수로 하여 반응표면모델(response surface model, RSM) 중심합성계획법으로 설계하였다. 백년초시료의 항산화능은 α, α-diphenyl-β-picrylhydrazyl (DPPH)-라디칼 소거 활성(%)법으로 측정하였고, CP 처리 조건과 라디칼 소 거 활성의 상관관계를 RSM 분석법으로 분석하였다. 시료의 친수성 관찰은 용해도와 분산안정성측정을 통해 이루어졌 고, 각각은 수용액상에 용해된 고형분의 비율(%, W/W)과 후방 산란의 변화(delta back scattering)로 측정되었으며, 쿼 세틴 함량은 HPLC로 정량분석하였다. 백년초 분말에 대한 최적 CP 형성 전력과 시간은 항산화능을 유지시키고 (p>0.05), 용해도를 2.3%만큼 증가시키며(p<0.05), delta back scattering을 0.47%만큼 감소시킨 856 W에서 36분으로 결 정 되었고, 백년초 추출물에 대한 최적 CP 형성 전력과 시간은 항산화능을 유지시키고(p>0.05), delta back scattering을 0.14%만큼 감소시킨 644 W에서 36분으로 결정 되었다. 최적 CP 처리 조건에서 백년초 분말과 추출물의 쿼세틴 함량 은 각각 2.7 μg/mL과 6.6 μg/mL 만큼 증가하였다(p<0.05). RSM 분석 결과 백년초 추출물의 항산화능은 CP 형성 전력 과 CP 처리 시간 조건에 영향을 받음을 확인할 수 있었으나(p<0.05), 선형 상관성은 보이지 않았다. 본 연구를 통해 CP 처리가 백년초 분말과 백년초 추출물의 항산화능 저감없이 친수성을 개선하는 것을 확인하였다. 백년초 분말과 백 년초 추출물의 식품 적용성을 증대시키는 기술로서 CP 처리의 가능성을 확인하였다.
Although carnosic acid (CaA) is known as one of the useful polyphenolic compounds due to its antimicrobial and antioxidant activities, it is limited to use as aqueous solution because of its low solubility and unstability. The objective of this study was to investigate the capability of CA to improve the solubility of CaA by forming an inclusion complex in comparison with cyclodextrin (CD) and maltodextrin (MD). Enzymatically-produced CA was reacted with CaA in aqueous solution to form a complex using a freeze-drying. And the formation of complex between CaA and CA was identified by X-ray diffraction (XRD), differential scanning calorimeter (DSC) and field emission scanning electron microscope (FESEM). As a result of XRD and DSC analysis, disappearance of characteristics of CaA that was reacted with CA could be indicated the complex formation between CaA and CA. The formation complex of CaA with CA was also confirmed through the change in morphology of CaA and CA in the electron micrograph result. Aqueous solubility of CaA with various concentrations (1, 5, 10, 20, 30%) of CA was measured by absorbance change at 285 nm. As a result, the solubility of the CaA was significantly increased with increasing CA concentration. At 30% CA, the maximum solubility of CaA was 0.095% (w/v) in solution, which was approximately 3 times higher than that of free CaA (0.033%). The effect of inclusion complex with CA on the solubility of CaA was superior than that with CD (0.057%) and MD (0.066%). These results indicated that the effects on the solubility and formation abilities of inclusion complex were associated with host materials and its concentration rate. This study confirmed that the CA can be a viable solution to improve the aqueous solubility of CaA. Further investigation is still needed to understand the effect of inclusion complex with CA.
To increase the stability of anthocyanin from black rice, β-cyclodextrin (β-CD) formed a complex with anthocyanin, and thermal and UVB stability of the complex was investigated at various pH levels. The formation of β-CD complex with anthocyanin was confirmed by the decreased UV-Vis spectrophotometer absorbance (at 511nm) with increasing the concentration of β-CD at pH 2, 2.5, 3, 4, and 5. ABTS (2, 2’-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid)assay was conducted to measure radical scavenging capacity (RSC) of the complex at pH 2, 4, 6, and 8, after which the RSCs were recorded over the 24 h heating(95°C) and 24 h UVB irradiating periods. The RSC values of the complexes increased as the β-CD concentration increased (0.1-2%) at pH 6 and 8. Upon thermal treatment, the RSC readings of the complexes tended to decrease to a lesser extent compared to the anthocyanin control (without β-CD) at pH 2. This result suggests that the thermal stability of anthocyanin was more retained in the presence of β-CD at low pH (pH 2). However, in the case of UVB irradiation, the effect of β-CD complex on the anthocyanin RSC was not significant, though the RSC values for both the anthocyanin control and complexes trended downward as the UVB irradiation time increased at all pH ranges except for pH 8 (no downward trend). In short, this study suggests that the effect of β-CD complex on the stability of anthocyanin antioxidant capacity depends on pH and the susceptibility to the degradation process.
A novel halophilic archaeon designated strain CBA1114T was isolated from solar salt in the Republic of Korea. Strain CBA1114T, which is a coccoid and stained Gram-negative, grew in the presence of 15-30% (w/v) NaCl (optimum, 20%) and at 20-50°C (optimum, 40°C) and pH 7.0-9.0 (optimum, pH 8.0). Strain CBA1114T required Mg2+ for growth. Strain CBA1114T had three 16S rRNA genes, rrnA, rrnB and rrnC; similarities between the sequences were 99.7 and 99.9%. The 16S rRNA gene sequence of strain CBA1114T showed a 91.7% similarity to that of Haloterrigena thermotolerans PR5T. In multilocus sequence analysis (MLSA), five housekeeping genes, atpB, EF-2, radA, rpoB’ and secY, were found to be closely related to those of the members of the genera Halorientalis (89.7% similarity of the atpB gene sequence), Halomicroarcula (91.9 %, EF-2), Haloterrigena (85.4 %, radA), Natronoarchaeum (89.2 %, rpoB’) and Natrinema (75.7 %, secY). A phylogenetic tree generated from the results of 16S rRNA gene and MLSA of the five housekeeping genes showed that strain CBA1114T was closely related to the species of the genus Halorientalis in the family Halobacteriaceae. The major polar lipids were identified as phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and unidentified lipids. According to the results of phylogenetic, phenotypic and chemotaxonomic analyses, we designate strain CBA1114T as Halostella salina gen. nov., sp. nov., which represents a novel species of a novel genus within the family Halobacteriaceae.
The freezing process of the freeze-drying procedure is important to optimize the physic-chemical properties of agricultural product. Therefore, our study was carried out to study the effect of freezing methods on the properties of freeze-dried apples. The sliced apples was frozen at -18°C as a general refrigerator (GR), -30°C with a individual quick freezing machine (IQF), and -80°C with deep freezer (DF), and subsequently, each sample was sublimated under 0.1 mbar for 24 hours. The samples were characterized by determination of color, texture properties, sugar contents, and morphology observation. The quality of color (L*, a* and b*) did not show significant discoloration. The hardness and sugar contents of IQF samples showed the greater value than GR and DF one. The morphology of IQF samples displayed the uniform and relatively small pore size as compared to GR and DF samples. From the sensory test, the IQF samples obtained the high score for overall acceptability, and consumer preference. From our results, the IQF treated apples are best results to produce good quality of freeze-dried apples.
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.
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.
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.
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.
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.
A study was conducted to determine the rheological properties of gochujang and chogochujang at different temperatures (25, 35 and 45°C). The rheological properties of the samples were determined using a rotational rheometer at a shear range of 1 to 40 s-1. The gochujang and chogochujang were found to be Non-Newtonian fluids following the Herschel-Bulkley model. The yield stress and consistency coefficient of the gochujang at different temperatures were higher than those of the chogochujang but the opposite was observed for the flow behavior index. Moreover, all rheological properties of the gochujang and chogochujang decreased with increasing temperature. The consistency coefficient was related to temperature using an Arrhenius-type relationship. The gochujang (14.48 kJ/mol) has higher activation energy than the chogochujang (14.03 kJ/mol). The yield stress values of the gochujang and chogochujang can be related to temperature by linear regression equations and the flow behavior index values by exponential regression equations.