The objective of this study was to increase the efficiency of starch extraction from potato sludge by different concentration of food-grade hemicellulase. The potato sludge, which is a by-product of potato processing industry, was treated with food-grade hemicellulase. Starch extraction efficiency displayed no significant difference in hemicellulase concentration. The purities of potato starch increased from 83.40 to 95.91, 97.44, 95.58, and 97.79%, with treated 0.5, 0.75, 1.0, and 1.5% hemicellulase, respectively. The physicochemical properties of the starches, such as granule structure, particle size, pasting, and thermal transition, were not affected by the concentration of hemicellulase. These results indicate that food-grade hemicellulase treatment is an efficient method for starch extraction from potato sludge.

The objective of this study was to determine rheological properties of cold water-soluble potato starch. Scanning Electron Microscopy (SEM) study showed that granule size of cold water-soluble potato starch was 10-60 μm, and shape was dimple in the middle, likely due to starch shrinkage after swelling during treatment. Cold water-soluble starch was prepared by ethanol (60%) and 3 M NaOH. The cold water solubility of native potato starch was low at 4.43±2.9%, whereas the solubility of cold water-soluble starch was high at 81.01±0.9%. The DSC diagram showed a gelatinization peak temperature of native starch but no such peak for treated starch. In dynamic tests, cold water-soluble starch showed decreased storage modulus (G') and loss modulus (G'') with increasing temperature, while native starch showed a continuous increase in G' and G''. This results indicated that cold water-soluble starch showed different granule structure and rheological properties.

Recently, amorphous granular starch (AGS) or non-crystalline granular starch (NGS) is of great interest because it has specific physicochemical properties compared to native starches. Various approaches have been taken to prepare gelatinized starch while still maintaining its granular shape. The granular cold-water soluble starch (GCWS) can be prepared by alcoholic-alkaline treatment or by using liquid ammonia and ethanol. However, these starches exhibit significant deformation and shrinking, and chemical treatments may raise safety issues for their potential food applications. Therefore, in this study, the optimization of preparation method for amorphous granular potato starch (AGPS) was investigated using ethanol and heat treatments. Response surface methodology (RSM) and central composite design (CCD) were used to find the optimum conditions for AGPS preparation based on granule integrity and birefringence. Optimum conditions were 53.3% ethanol and 93.87oC heat treatment for 15 min. Prepared AGPS maintained its granular structure and lost birefringence, crystallinity, and DSC amylopectin melting peak, suggesting that proper AGPS could be made using optimized conditions.

The objective of this study was to increase starch extraction efficiency from domestic potato by five kinds of foodgrade cellulases (mixture of β-glucanases, pectinase, cellulase, hemicelullase, and β-glucosdiase). Cellulase-treated potato had a maximum of 40% higher starch extraction yield than non-enzyme treated potato. It turned out that the shape and structure of cellulose-treated and nonenzyme-treated potatoes were the same. The average particle size of cellulose-treated potato starch was smaller than non-enzyme treated potato. Interestingly, the small starch granular (<10 μm particle) was shown in extracted starch from cellulose-treated potato. Rapid viscosity analysis showed that starch from cellulase treated potato had lower pasting temperature than starch from nonenzyme-treated potato. The range of the gelatinization temperature (49-62oC) of starches from cellulose-treated potato was broader than that of starches from nonenzyme-treated potato. Therefore, the results of this study confirm that cellulase plays an important role in the extraction of starch from the potato and physicochemical characteristics of potato starch.

감자가루의 페이스팅 점도 특성에 영향을 미치는 감자전분의 특성 요인을 결정하기 위해 6품종의 황색육질의 감자로부터 제조된 감자가루의 성분분석과 페이스팅 점도 특성을 조사하고 감자가루로부터 추출한 감자전분의 물리화학적 특성을 분석하여 감자가루의 페이스팅 점도특성과 상관관계를 분석하였다. 감자가루의 총 전분 함량은 이의 페이스팅 점도 특성치들과 높은 상관성을 보유하고 있었다.감자전분의 아밀로오스 함량은 감자가루의 최고점도와 음의 상관관계를 나타내었으나 인 함량은 감자가루의 최저점도, 붕괴점도, 최종점도, 및 노화점도들과 유의적인 상관성을 존재하였다. 또한 감자전분의 인 함량에 의해 높은 영향을 받는 팽윤력은 인 함량과 감자가루의 페이스팅 점도특성들 사이에서 관찰된 상관관계와 유사하였다. 감자전분의 아밀로펙틴 분지사슬 분포에 있어 F1 및 F3 분획 분포들은 감자가루의 페이스팅 점도 특성치들과 높은 상관성을나타내었다. 감자전분의 페이스팅 점도 특성치들 중 최종점도는 감자가루의 페이스팅 점도 특성치들 모두와 유의적으로 높은 상관성을 보유하였다. 본 연구의 결과들을 종합할 때 감자전분의 아밀로오스 함량, 인 함량, 팽윤력, 아밀로펙틴의 짧은 분지사슬(DPn<25) 분포와 감자전분의 최종점도가 감자가루의 페이스팅 점도 특성을 예측할 수 있는중요한 특성요인일 것으로 판단된다.

가공식품의 원료로 널리 사용되고 있는 옥수수, 감자, 고구마 전분에 멥쌀 및 찹쌀로부터 분리한 전분을 일부(10-30%) 대체하여 신속점도측정기(RVA)로 호화특성을 조사하였다. 쌀 전분은 호화개시온도가 옥수수, 감자, 고구마전분에 비해 낮았고 페이스트 점도가 타 전분에 비해 낮은 경향이었다. 멥쌀 전분의 호화개시온도는 찹쌀 전분에 비해높았으며 최고점도, breakdown이 보다 높게 나타났다. 옥수수 전분에 멥쌀 및 찹쌀 전분을 10-30% 대체하여 RVA 호화양상을 측정한 결과 쌀 전분의 첨가는 RVA 최고점도, trough 점도를 증가시켰으나 최종점도에는 큰 증가세를 보이지 않아 setback은 다소 감소하는 경향이었다. 찰옥수수 전분에 쌀 전분의 첨가는 옥수수 전분과는 달리 RVA 최고점도를 감소시켰으며 최종점도는 증가세를 나타내 setback이 증가하는 것으로 나타났다. 감자 전분에 쌀 전분의 첨가는 최고점도, trough 점도, 최종점도를 다소 감소시켰으나 여전히 높은 점도를 유지하는 것으로 나타났으며setback 역시 여전히 낮게 유지됨을 보여주었다. 고구마 전분에 쌀 전분의 첨가는 전분 paste의 최고점도, trough, 최종점도가 감소하는 결과를 초래하였다. 밀가루에 쌀 전분을 대체시에 멥쌀 전분은 밀가루의 페이스트 점도를 증가시키는 반면에 찹쌀 전분은 전반적으로 점도를 감소시키는 것으로 나타났다.

Ohmic heating uses electric resistance heat which occurs equally and rapidly inside of food when electrical current is flown into. In other study, we researched about soybean protein’s characteristic changes by ohmic heating. Nevertheless treated same temperature, denaturation of soybean protein were accelerated by ohmic heating than conventional heating. In this time, we studied thermal property change of potato starch by ohmic heating besides conventional heating. For this purpose, potato starch was heated at same subgelatinization temperature by ohmic and conventional heating. And thermal properties were tested using DSC. Annealing of starch is heat treatment method that heated at 3～4% below the gelatinization point. DSC analysis results of this study, the T_o, T_p, T_c of potato starch levels were increased, whereas T_c～T_o was narrowed. This thermal property changes appear similar to annealing’s result. It is thought the results shown in this study, because the heating from below the gelatinization point. 6, 12, 24, 72, and 120 hours heating at 55℃ for potato starch, T_o, T_p, T_c values continue to increased with heating time increase. The gelatinization temperature of raw potato starch was 65.9℃ and the treated starch by conventional heating at 55℃ for 120 hr was 72℃, ohmic was 76℃. The gelatinization range of conventional (72 hr) was 10℃, ohmic was 8℃. In case of 24 hours heating at 45, 50, 55, 60, 65℃ for potato starch, the result was similar to before. T_o, T_p, T_c values continue to increased and gelatinization range narrowed with heating temperature increase. In case of conventional heating at 60℃, the results of gelatinization temperature and range were 70.1℃ and 9.1℃. And ohmic were 74.4℃ and 7.5℃. When viewed through the results of the above, the internal structure of starch heated by ohmic heating was found that the shift to a more stable form and to increase the homology of the starch internal structure.

This study was performed to analyze the effects of ultra fine pulverization (UFP) on the physicochemical properties of sweet potato starch (SPS). The average diameter and specific surface area of the SPS was decreased from 22.94 to 10.25 μm and from 0.879 to 1.909 m2/g throughout UFP, respectively, and the damaged starch content was increased from 13.7 to 99.2%. The pulverized sweet potato starch (PSPS) had higher swelling power, solubility, and transmittance values than the SPS. X-ray diffractograms revealed that the SPS had a C-type pattern, which disappeared in PSPS. The rapid visco analysis (RVA) characteristics, peak viscosity, break down, and set back of SPS ceased to exist in PSPS. According to differential scanning calorimetry (DSC) curves, the peak temperature (Tp) and gelatinization enthalpy (ΔE) of SPS were 71.95oC and 10.40 J/g, respectively, while these remained undetected in PSPS. The enzymatic digestibilities of SPS and PSPS were 61.7 and 84.7%, respectively.

Developing carbohydrate fat replacer as materials for low-calorie and low-fat food made of Korean potato, it is expected that the new demand of fat replacer will be created. Potato starch was modified by chemical modification. Observing modified starch(treated in different method) by SEM, EZ(treated by enzyme) showed shape of deformed round oval, AC(treated by acetylation,), HPR(treated by hydropropylation) showed shape similar to that of NL(N-Lite), the commercial fat replacer. In the modified starch such as AC, peak in B and C type similar to those of general starch was found, but EZ showed non-crystalline shape. Compared to other modified starch, HPR, the chemically produced denatured starch showed very peculiar peak and structure in V-form. While the order of contents of amylopectin was in the order HPR 〉 EZ 〉 AC showed extremely high contents. Measuring the degree of gelatinization per the modified method, the degree of gelatinization of HPR as much higher than others. The water binding activity of modified starch was 240% in HPR. Measuring viscosity by producing general starch and modified starch as gel of 10% concentration, the CPS showed very high viscosity of 30.30 × 103 cp. Showing viscosity of 38.60, 31.60 103 × cp, the modified starch was in the order of HPR. While the calorie of starch of GPS was measured to be 3.0 Kcal/g, very low calorie those of chemically modified starch, HPR showed 2.5 Kcal/g respectively, suggesting that calorie is decreased by modified treatment. The appropriateness of processing food was experimented by substituting the existing oil and fat containing food with saturated gel of starch and modified starch in constant rate through utilization of modified starch. Therefore, research and development for materials and related products which maintain the existing quality and reduce fat contents will be constantly performed in the future.

This study was conducted to investigate the quality characteristics of low- fat pork patties containing fat replacers. Carrageenan(CA) in combination with pectin(PE) or potato starch(PO) was added as fat replacers and physicochemical properties were evaluated in low-fat pork patties cooked by oven-roasting or pan-frying. Uncooked and cooked pork patties formulated with fat replacers were higher in moisture and ash content and lower in fat content than those of control. The cooking yield and reduction in diameter of pork patties were significantly improved by the addition of fat replacers(p<0.05). Pork patties formulated with CA had the highest fat retention, while CA+PE had the highest water holding capacity. Hunter s L(lightness) value was not different from among patties and a(redness) and b(yellowness) values were higher in carrageenan-based patties than those of control patties. Hardness was higher in carrageenan-based patties than that of control and cohesiveness and springiness showed no difference among patties. Sensory analysis showed that flavor, juiciness and palatability of carrageenan-based patties were superior to control patties and combined use of CA with PE or PO provided improved acceptability of low-fat pork patties over that from using single carrageenan.

본 연구는 망실 하우스 내에서 봄감자 재배 시. brushing 처리가 감자의 도장 방지와 생육과 수량 및 체내 전분함량에 미치는 효과를 구명하기 위하여 수행하였다. 지상부의 생육은 생육 후반기로 갈수록, brushing 처리시간이 길수록 감소하였다. 측지 수도 처리시간이 길수록 감소하는 경향이었다. 경장과 경경은 5월 6일에는 처리간에 비슷하였으나 생육 후반기로 갈수록 모든 처리에서 증가하였는데 평균적으로 30∼36mg/100 cm2였다. 지상부ㆍ지하부의 생체중과 건물중은 처리시간이 긴 것이 무거웠고, 전분 함량은 무처리에 비해 brushing 처리한 것이, 그리고 처리시간이 긴 것이 높았다.

‘오륜(Oryun)’은 강원도농업기술원 특화작물연구소에서 ‘대서(Atlantic)’를 모본으로, 페루 수집종 ‘CIP705’를 부본으 로 인공교배한 후 2012년에 선발 육성된 품종이다. 2010년부 터 2012년까지 3년간 특성검정과 지역적응시험을 수행하였 다. ‘오륜(Oryun)’의 생장 습성은 반직립형이며 초세가 강하 고 내도복성이다. 괴경 크기는 편원형이며, 꽃색은 흰색이며 표피색은 황색, 육색은 백색이다. ‘오륜(Oryun)’의 휴면기간 은 90～100일로 ‘수미(Superior)’ 보다 5～10일 정도 길다. ‘오륜(Oryun)’의 지역적응시험 결과 상품 수량은 ha당 36.8 M/T이며 괴경의 평균비중은 1.080으로 ‘수미(Superior)’에 비해 높다. 또한 역병에 비교적 강하여 친환경재배에 알맞은 품종이다.

‘전미’는 2009년에 농촌진흥청 바이오에너지작물센터에서 전분용 고구마로 개발되었다. 이 품종은 ‘진홍미’를 모본으로 하고, 99IT55-2를 부본으로 하여 선발되었다. 2001부터 2003 년까지 계통선발시험과 2004년부터 2005년까지 2년 동안 생 산력검정시험을 수행하였고, 2006, 2008, 2009년 3년간 무안 등 전국 6개 도에서 지역적응시험을 수행하였다. ‘전미’의 엽 형은 심장형이고, 줄기 및 잎자루색은 녹색이다. 고구마 모양 은 방추형으로 표피색은 자색, 육색은 담황색이다. 선충 및 덩 굴쪼김병 저항성은 ‘중강’이며, 검은썩음병과 연부병도 ‘중강’ 이다. 전분가는 25.6%로 ‘율미’보다 높고, 전분수량은 6.8 t/ha 으로 ‘율미’ 보다 26% 높다. 총당 함량은 ‘전미’가 3.59 g/100 g, dry weight으로 ‘율미’에 비하여 20%가 높다. 당 종류별로 는 sucrose가 2.53 g/100g, dry weight으로 가장 많이 함유되 어 있다. ‘전미’의 조기재배 수량은 3개년 평균 26.1 t/ha으로 ‘율미’에 비하여 147%로 수량이 증수되었고, 만기 및 적기재 배는 26.2 t/ha으로 ‘율미’ 대비 139%로 수량이 높다. 조기재 배의 경우 주당 상품괴근수는 ‘전미’가 3.0개/주로 ‘율미’와 동일하였고, 상품괴근평균중은 151 g/개로 ‘율미’보다 12% 높다. 또한 만기 및 적기재배의 경우 주당 상품괴근수는 평균 3.0개/주로 ‘율미’ 2.3개/주개보다 많고, 상품괴근평균중은 178 g/개로 ‘율미’ 보다 높다.