不同品种紫薯全粉基本成分及特性研究

对6个品种紫薯全粉的基本成分进行了测定,对其持水性、吸油率、冻融稳定性等特性进行了分析.结果表明,徐紫3-73淀粉含量最高,冻融稳定性最好,适宜添加到速冻食品中;烟紫337与徐紫201吸油率较高,适宜添加到煎炸食品中;京6蛋白质含量最高,透光率最低,直链淀粉含量较高,适合添加到膨化食品中;宁紫1全粉糊粘度最低,表明细胞完整度高,营养物质保留较好;山川紫支链淀粉含量较高,持水性较好,表现出较好的抗老化能力,能够提高面团的吸水性.     

不同品种甘薯的干燥特性及对全粉品质的影响

以9个甘薯品种为原料,研究不同品种甘薯在相同工艺条件下的干燥特性,分析甘薯品种与其全粉品质及得率的相关性。结果表明:鲜薯成分中影响熟化甘薯热风干燥速率的因素主要是可溶性糖含量,而影响颗粒全粉得率及品质的因素主要是水分、淀粉、可溶性糖、粗蛋白含量及多酚氧化酶、β-淀粉酶活性。鲜薯的水分含量及可溶性糖含量越低,淀粉含量越高,加工成颗粒全粉的产品得率越高。     

Water desorption isotherms of two varieties of sweet potato

Water desorption isotherms were determined for New Zealand sweet potato at 25, 40 and 55°C, and for Philippines sweet potato at 28°C. The isotherms were sigmoid in shape and of type II according to the BET classification. The data were fitted to eight two-parameter equations reported in the literature. The effect of water activity, a_w, and temperature, T °C, on the equilibrium moisture content, M _e g water/100g dry solids, was best described for New Zealand sweet potato by: Me = 20.51 T-^0.204 (a_w/(1-a_w)0.39 for a_w= 0.06–0.81     

Physicochemical properties of sweet potato starch

Tropical root crops, of which the sweet potato is an important representative, constitute an under exploited resource of developing countries. They can be used as food for both human and animal consumption and their starch is a source of industrial raw material. This review will consider recent reports on sweet potatoes, the physicochemical properties of their starches in comparison with other starches, and the possible causes of variation in these characteristics.     

高产酒精酵母菌株及甘薯品种筛选

以酒曲中筛选到的酵母菌A4为出发菌株,用紫外线对其原生质体进行物理诱变,经过三级筛选得到突变高产菌株A4-20。以麦芽汁为基质发酵72h后,酒精度为4.93%,较出发菌株提高了28.7%。经过连续转接10代,A4-20的发酵性能表现稳定。用其对6种高淀粉品种甘薯淀粉进行发酵实验,得出3个品种的酒精产量均达14%以上,其中徐薯22酒精产量达到最高14.87%,出酒率为38.1%,经比较,徐薯22、皖薯3号和199031-1更适合应用于酒精产业。     

不同品种甘薯生湿面条品质特性及加工适宜性分析

为了研究不同甘薯品种加工甘薯生湿面的适宜性,以38个甘薯为原料制作生湿面,分别测定甘薯的质构(texture profile analysis,TPA)、水分、灰分、淀粉、还原糖和总糖等加工指标以及甘薯生湿面的质构(TPA)和蒸煮损失率等品质指标,采用相关性分析、主成分分析和回归分析方法建立甘薯生湿面综合评价指标与甘薯原料加工指标之间的回归模型,然后通过K-means聚类法对38个甘薯品种的生湿面综合评价指标进行初步聚类。结果表明,适宜加工甘薯生湿面的品种有17个,基本适宜加工甘薯生湿面的有12个,不适宜加工成甘薯生湿面的品种有9个,评价结果与实际应用相符合。该研究可为甘薯生湿面加工专用品种的筛选提供一定的理论依据。     

Textural character of sweet potato root of Korean cultivars in relation to chemical constituents and their properties

A relationship between chemical constituents and physicochemical and textural properties of different Korean sweet potato (SP) cultivars were investigated in terms of the hardness of raw and cooked root, alcohol insoluble solid (AIS), starch and amylose content, amylase activities, and pasting properties. Correlation coefficients were analyzed and principal component analysis was performed. The hardness of cooked root was found to correlate with the hardness ratio of cooked/raw SP, AIS content (0.75**), starch content (0.64**), and peak viscosity of SP powder (0.56*). It was discovered that SP cultivars could be classified into mealy (Sincheonmi, Daeyumi, Sinyulmi), intermediate (Dahomi, Sinjami, Geonhwangmi, Yeonjami, Pungwonmi), and waxy (Juhwangmi, Sinhwangmi) types depending on the first principal component (PC1, 68%). Therefore, it was found that the texture types of SP cultivars could be predicted from hardness of cooked root and are in relation to AIS and starch contents, and peak viscosity of raw powder.     

甘薯淀粉糊性质的研究

甘薯淀粉是重要的粮食、饲料和工业原料.淀粉的应用主要是应用淀粉糊,因此糊的性质至关重要.本文采用Brabender连续粘度计测定了甘薯淀粉在不同浓度、pH、食糖、盐和硬脂酸条件下对甘薯淀粉糊粘度曲线的影响;并对甘薯淀粉糊的透明度、凝沉性和冻融稳定性等进行了测试,为进一步开发甘薯淀粉的应用提供基础.     

Physicochemical properties of twenty-one Caribbean sweet potato cultivars

The physical, chemical and physicochemical properties of twenty-one Caribbean sweet potato cultivars were investigated. Hunter L a b colour parameters were measured, chroma, colour intensity and hue angle were calculated. Proximate composition, vitamin C, amylose, reducing and non-reducing sugars contents were determined using standard methods. Pasting properties were determined using Rapid Visco Analyser. Tuber size (length, r  = 0.72, n  = 21, P  < 0.0015; width, r  = 0.85, n  = 21, P  < 0.0002) was highly correlated with weight of the tubers. External colours of the tubers ( L =  28.7–63.1, a =  +5.9 to +18.0, b =  +3 to +19.3) were lower than the flesh colours ( L =  60.8–84.0, a =  −2.4 to +27.8, b =  +9.9 to +28.5). Proximate composition is typical of sweet potato cultivars but significant differences exist among cultivars. Total sugar, amylose and amylopectin contents ranged from 1.8 to 4.7%, 15.3–31.2% and 68.8–84.7%, respectively. Cooking profiles of the sweet potato flours showed similar trend. Pasting temperature, peak time, swelling power and solubility ranged from 78.3 to 93.0 °C, 3.3–4.8 min, 5.6–23.5 and 11.7–45.7%, respectively.     

甘薯淀粉性质的研究

研究了甘薯淀粉的理化性质,结果表明:其颗粒粒径的平均值为5~31mm,结晶结构属C型,直链淀粉含量18.5%,糊化温度为60.8~78.5℃。甘薯淀粉的透明度为42%,凝胶强度为98g。     

红薯抗性淀粉的结构表征及性质测定

目的:研究超声酸解法制备的红薯抗性淀粉的结构和性质。方法:通过红外光谱(IR)、扫描电镜(SEM)、差示扫描量热法(DSC)及X-射线衍射(XRD)分析技术分析比较了红薯原淀粉和红薯抗性淀粉的结构,并测定了淀粉的的含水率、乳化性、透明度和比容积等性质。结果:淀粉形貌由原来表面光滑的多面体小颗粒状变为表面有褶皱的蓬松的大块片状结构,晶型由A型转变为B型,结晶度增大,热稳定性提高。抗性淀粉的含水率、乳化性、透明度和比容积降低,而持水性增加。结论:红薯抗性淀粉可以作为添加剂用于功能食品的研究开发。     

Antioxidant capacity of japchae,Korean stir-fried sweet potato noodles with vegetables

Antioxidant capacities of japchae, a Korean traditional food were investigated. Japchae showed concentration dependent radical scavenging abilities with half maximal inhibitory concentration values (IC₅₀) of 0.68 and 1.36 mg/mL from DPPH and ABTS assays, respectively. Positive correlations were observed between radical scavenging effects and the contents of total polyphenol (TPC), retinol, β-carotene, and ascorbic acid. Lipid peroxidation was inhibited by japchae with IC₅₀ values of 1.49 and 1.40 mg/mL based on ferric thiocyanate (FTC) and thiobarbituric acid reactive substances (TBARS) assays, respectively.     

Physicochemical properties of mung bean starches in different Korean varieties and their gel textures

To compare the mung bean starches (MBS) and starch gel properties, Korean varieties, ‘Geumsung‘, ‘Dahyeon‘, ‘Sohyeon’ and ‘Eohul‘, were purified using water and alkaline steeping methods. The physicochemical properties of starches, the texture and structure of starch gels were investigated. The apparent amylose and protein contents were significantly different depending on varieties and steeping mediums. Water binding capacities were higher in ‘Geunsung’ and ‘Eohul‘. The granule sizes were ranged 7.8–23.3 μm and the shapes were oval and jelly bean, and ‘Dahyeon’ granule had a distinct hilum. The trough, final, and setback viscosities were significantly different and the viscosities of ‘Sohyeon’ showed lowest values. MBS gels formed a regular shaped 3-dimensional network. The gel structure of ‘Sohyeon’ changed irregularly during storage, but the structures of ‘Geumsung‘, ‘Dahyeon‘, and ‘Eohul’ retained regular shaped networks with decreasing inner cells. Resilience of MBS gels was higher in ‘Dahyeon’ and ‘Eohul’ than in ‘Geumsung’ and ‘Sohyeon‘.     

不同烹饪方法对番薯营养成分的影响

研究了蒸、煮、油炸、微波等4种不同烹调方法对番薯感官品质及淀粉、Vc、还原糖、蛋白质、花青素等营养成分的影响。结果表明:与生番薯相比较,各种烹饪方法均导致番薯营养物质的损失,尤以油炸损失率最高;煮法中番薯部分营养成分流入汤汁中,而蒸法和微波能较好地保持番薯的营养品质。仅从营养成分保持而言,微波是番薯最佳的烹饪方法。     

甘薯果胶物化特性的研究

以购买的柑橘果胶和苹果果胶作为对照,分别比较了甘薯果胶与这两种果胶颜色、溶解度、黏度、乳化特性等物化特性的差异,并分析了甘薯果胶的糖构成成分。结果表明:甘薯果胶的溶解度、黏度略低于柑橘果胶,高于苹果果胶,并且具有较好的乳化稳定性。同时,甘薯果胶中半乳糖醛酸和葡萄糖的含量较高。     

甘薯淀粉-魔芋葡甘露聚糖膜性能研究

可食用性包装材料被认为是可以直接被食用的特殊包装材料,可食用性淀粉包装薄膜是其研究和应用最为广泛的一种,而其中的甘薯淀粉薄膜更是具有代表性。本文主要探索和研究不同浓度魔芋葡甘露聚糖的加入对甘薯淀粉薄膜的拉伸强度、吸湿度、透气性、透湿性和色差等指标的影响,希望能为进一步加快可食用性淀粉膜的深层技术开发、相关产品能够早日面市和大规模应用提供一定的数据参考。研究的结果表明:当魔芋葡甘露聚糖浓度(g/100g淀粉)为3%7%时,薄膜的断裂伸长率有上升,将对薄膜的脆性有一定的改善;当淀粉浓度在4%时,薄膜的抗张强度和断裂伸长率均有较好表现。另外魔芋葡甘露聚糖的添加使透湿性和透气性都有显著的降低,但对薄膜色泽的影响不明显。     

甘薯交联抗性淀粉热力学性质与消化性研究

根据膨胀度、糊化度及差示扫描量热仪(DSC)测得热力学参数,综合分析甘薯交联抗性淀粉和原淀粉热力学性质,并采用Jenkins提出In–vitro模型测定淀粉体外消化性。结果表明:在同一温度下,甘薯交联抗性淀粉膨胀度和糊化度均较原淀粉低,且交联剂用量越高,淀粉膨胀度和糊化度越小;DSC测试结果显示,甘薯交联抗性淀粉相转变温度To、Tp、Tc随交联剂用量增加而升高,Tc–To和△H均比原淀粉低。In–vitro消化模拟实验表明,甘薯交联抗性淀粉消化性比原淀粉低,并随交联剂含量增加,消化产物量减少,消化速度降低。     

Change in dielectric properties of sweet potato during microwave drying

Food Science and Biotechnology - Sweet potato slices and strips (thickness of 6 and 9&nbsp;mm, respectively) as single layer were dried at different microwave power levels (90&nbsp;W to...     

食用交联甘薯淀粉制备与性质研究

以甘薯淀粉为原料,三偏磷酸钠为交联剂,对甘薯淀粉进行变性,制备食品用交联甘薯淀粉。以交联淀粉峰值粘度和结合磷含量为指标,以三偏磷酸钠用量、反应pH、温度、时间和硫酸钠用量为因素研究交联反应最优工艺;并研究系列食用交联甘薯淀粉粘度、溶解度、膨胀度、透明度、凝沉性、冻融稳定性等理化性质及形态学和结构性质,为其在食品中应用提供理论依据。     

How sweet potato varieties are distributed in Uganda: actors, constraints and opportunities

Sweet potato varieties are distributed in Uganda by three systems: formal, project-based and informal. In a partial formal system, the National Sweetpotato Program (NSP) breeds and tests both orange (O)- and white (W)-fleshed sweet potato (FSP) varieties. The NSP and other national institutions provide vine stocks of mostly OFSP varieties to project-based seed systems involving large private sector multipliers, which are found predominantly in east and central Uganda. These are mainly either cooperatives derived from smallholder groups organized by projects or are individual farmers with large holdings who had hosted NSP variety trials. The private sector multipliers sell planting materials of released varieties to projects, which distribute them free to selected households. Projects buy hundreds and occasionally thousands of sacks of vines but they distribute them to only a limited number of needy households and for only one or a few seasons. The informal system functions predominantly in areas with a long dry season, in which vines cannot survive. Its vine multipliers use the wetter lowlands to maintain mostly landraces, which they sell as small bundles of vines to many smallholders at the onset of the rains. Very few multiply released varieties. Thus, with a ready market, the system is sustainable but quantities sold are price limited. All vine multipliers supplied healthy planting material. It is proposed that the NSP should aim their trials of new varieties at informal vine multipliers and projects should supply vines to these multipliers in order to improve their access to them. This would promote the sustainable distribution of vines, including new varieties, over a greater area and to a larger number of farmers.