Reduction of polyphenol and phytic acid content of pearl millet grains by malting and blanching

This work was undertaken to evaluate the changes in polyphenol and phytic acid content in malted and blanched pearl millet grains. For malting, grains were steeped for 16 hours, germinated for 48 or 72 hours and then kilned at 50 ^°C for 24 hours. Blanching was done for 30 seconds in boiling water at 98 ^°C. Results indicated that blanching resulted in significant reduction in polyphenol (28%) and phytic acids (38%). Destruction of polyphenols (38 to 48%) and phytic acid (46 to 50%) was significantly higher in grains subjected to malting than blanching. The overall results suggested that malting with 72 hours of germination was most effective in reducing the antinutrient levels of pearl millet grains.     

Levels of β-carotene and effects of processing on selected fruits and vegetables of the arid zone of India

Some locally available fruits and vegetables of the arid zone of Rajasthanwere analyzed for their -carotene content; the selected fruits and vegetables were: Dansra (Rhus myserensis), Kachri (Cucumis collosus), fruit Kachri (Cucumis collosus), Kair (Capparisdecidua) and Sanghri (Prosopis cineriria). The -carotene contents of the samples were estimated in fresh and various processed states (blanched, dried and roasted). The results showed the heat lability of -carotene. Among the samples, kair was found to be the richest source of -carotene. Variety, too, had an impact on the content of this fat soluble vitamin.     

Nutritional composition of selected green leafy vegetables,herbs and carrots

Six green leafy vegetables and herbs – spinach, amaranth, bengal gram, cauliflower, mint, coriander and carrots – were analyzed for moisture, protein,ascorbic acid, -carotene, total iron, ionizable iron (as % of total iron) in vitro iron (% of total iron), copper, manganese and zinc. Moisture content of the leaves and carrots varied from 75.1 percent (bengal gram) to 95.4 percent (carrot) and protein from 9.83 percent (carrots) to 30.9 (mint) percent. Ascorbic acid, -carotene, total iron and ionizable iron contents were at a maximum in case of bengal gram leaves whereas level of ionizable iron and in vitro iron as a percent of total iron was highest in carrots. Copper, manganese and zinc contents were maximum in spinach.     

干制荔枝果肉预处理的烫漂与护色工艺

为减轻荔枝果肉热风干制期间的褐变,研究荔枝果肉的烫漂和护色工艺。通过L9(34)正交试验设计,研究烫漂温度、烫漂时间和冷却方式对荔枝果肉多酚氧化酶(PPO)的钝化效果,比较不同浓度配比护色液对荔枝果肉干制品色泽和感官品质的影响。结果表明:当烫漂温度为100℃,烫漂时间为3 min,室温冷却时烫漂效果最好;当复配护色剂的浓度配比为0.10%抗坏血酸+0.20%柠檬酸+0.10%植酸+0.30%Ca Cl2时,荔枝果肉干制品的色泽和感官品质最佳。     

菊苣家庭简易软化栽培方法的比较研究

以芽球菊苣为试材,从产量、品质、病害发生率、转化率、成品率以及经济效益方面,比较了3种家庭简易软化栽培方式的效果.结果表明,以锯末为基质的锯末软化栽培法效果最佳,其肉质根所储养分转化充分,芽球产量最高,品质好,且发病率低.锯末软化栽培法是一种简单实用的无土软化栽培方法.     

Effect of home processing and storage on ascorbic acid and β-carotene content of bathua (Chenopodium album) and fenugreek (Trigonella foenum graecum) leaves

The present investigation was conducted to study the effect of selected processing and storage methods on the concentration of ascorbic acid and β-carotene in Bathua and fenugreek, leaves. Methods included storage of leaves with or without polythene bags for 24 and 48 h in a refrigerator at 5°C; at 30°C in polythene bags; drying (sun and oven); blanching (5, 10, 15 min); open pan and pressure cooking. Ascorbic acid content of fresh leaves was 220.97 to 377.65 mg and β-carotene content was 19.00 to 24.64 mg/100 g, DW. The percent loss of ascorbic acid ranged from 2.03 to 8.77 and 45.15 to 66.9 while lower losses (0.0 to 1.75 and 1.63 to 2.84) of β-carotene were observed in leaves, stored in, the refrigerator and at 30°C, respectively. A markedly greater reduction in ascorbic acid and β-carotene was observed in dried, blanched and cooked leaves. The study data suggest that storage of leaves in refrigeration, drying in oven, blanching for a short time and cooking in a pressure cooker results in better retention of these two vitamins.     

杀青工艺对柿叶绿茶活性成分的影响

研究了杀青工艺条件对安溪油柿叶绿茶类黄酮、维生素C、多酚和游离氨基酸等活性成分的影响。结果表明:柿叶鲜叶不切,直接以炒青机炒青有利于保留柿叶绿茶类黄酮、多酚和游离氨基酸等活性成分;低温短时杀青有利于柿叶绿茶活性成分的保留,杀青条件以120℃,1min最佳。     

枸杞嫩茎叶干制工艺研究

以枸杞嫩茎叶为材料,研究了热风干燥条件下的较优加工工艺参数。结果表明：采用0.04%的Zn（CH3COO）2＋0.02%的Na2SO3的混合液作为护绿剂效果好于锌铜护色;漂烫温度95-100℃、漂烫时间100 s有利于保持色泽和营养成分;用4%的蔗糖溶液浸泡30 min,可以明显改善制品的复水性。     

预处理工艺参数对脱水甘蓝加工品质的影响

以甘蓝为原料,通过考察Vc含量、色泽变化,研究常压热风干燥下浸渍、漂烫、护绿等预处理工序中不同工艺参数对脱水甘蓝加工品质的影响。经单因素、正交实验研究,结果表明:所得脱水甘蓝品质最佳为:NaHCO3溶液浓度0.25mol/L,漂烫温度为90℃,漂烫时间45 s,护绿剂最佳配比为200mg/LZn(AC2)0∶.3%CaCl28∶00 mg/LMgCl21∶00mg/LEDTA=33∶2∶1∶,护色时间为30 min。     

麦瓶草护绿研究

［目的］研究麦瓶草的护绿方法,为开发切实可行的麦瓶草产品提供科学依据和理论指导。［方法］以麦瓶草为材料, 采用碱性溶液热烫法和金属离子置换法处理,并测定处理后麦瓶草的外观色泽等级与叶绿素含量。［结果］结果表明： 碱性溶液热烫法护绿效果较差,各因素影响的显著性顺序为热汤温度〉热烫时间〉pH,其中热烫温度为极显著,热烫时间为显著,最佳组合为92 ℃、4.5 min、 pH值 7.5;金属离子置换法护绿效果好,各因素影响的显著性顺序为Zn^2＋〉Cu^2＋〉Mg^2＋,其中Zn^2＋和Cu^2＋的影响为极显著,最佳组合为Zn^2＋200 mg/L、Cu^2＋100 mg/L、Mg^2＋200 mg/L。[结论］从处理后麦瓶草的外观与叶绿素含量角度来看,金属离子置换法明显优于碱液热烫法。