结球甘蓝不同品种及部位中主要生物活性物质含量比较

对春大将、帕特、汉城和春优4种结球甘蓝(Brassica oleracea var.capitata L.)以及帕特甘蓝的不同部位中硫代葡萄糖苷、异硫氰酸盐(isothiocyanate,ITCs)、总酚和抗坏血酸等主要生物活性物质含量进行比较。结果表明:各品种中脂肪族硫苷含量均最高。其中帕特甘蓝中总硫苷、脂肪族硫苷均高于其他3个品种,且其不同部位中总硫苷含量以外部叶为最高,而中部叶中含量最低。帕特甘蓝中ITCs和总酚含量最高,汉城甘蓝中抗坏血酸含量高于其他3个品种;春大将甘蓝中黑芥子酶(myrosinase,MYR)活性最高,帕特和春优甘蓝中其活性差异不显著,汉城甘蓝中最低。帕特甘蓝中ITCs和抗坏血酸含量以外部叶为最高,总酚含量则在内部叶中最高,MYR活性在中部叶和内部叶中显著高于外部叶。可见,帕特甘蓝可作为功能性食品的原料加以开发利用。     

Effects of Boiling on Dietary Fiber Components in Fresh and Stored White Cabbage (Brassica oleracea var. capitata)

The effects of boiling (10 min) and how differences in cultivars (n= 6), maturity (n= 2), and storage (n= 3) may affect dietary fiber in white cabbage were studied. A great variation in total dietary fiber content between boiled cabbage samples was seen (17.7 to 31.7 g/100 g dry weight basis). Total and insoluble dietary fiber following boiling could be predicted from the initial amount. Average losses for early and late cultivars were similar (about 10%) and were mainly due to insoluble polymers consisting of glucose and partly of uronic acids. The early cultivar ‘Balbro’ was least affected by heat treatment: only 2% total dietary fiber was lost. Harvesting before physiological maturity and short‐term storage increased the loss of soluble polymers (pectic substances), whereas long‐term storage decreased the loss.     

Thermal Stability of l-Ascorbic Acid and Ascorbic Acid Oxidase in Broccoli (Brassica oleracea var. italica)

ABSTRACT: The thermal stability of vitamin C (including l -ascorbic acid [l -AA] and dehydroascorbic acid [DHAA]) in crushed broccoli was evaluated in the temperature range of 30 to 90 °C whereas that of ascorbic acid oxidase (AAO) was evaluated in the temperature range of 20 to 95 °C. Thermal treatments (for 15 min) of crushed broccoli at 30 to 60 °C resulted in conversion of l -AA to DHAA whereas treatments at 70 to 90 °C retained vitamin C as l -AA. These observations indicated that enzymes (for example, AAO) could play a major role in the initial phase (that is, oxidation of l -AA to DHAA) of vitamin C degradation in broccoli. Consequently, a study to evaluate the temperature–time conditions that could result in AAO inactivation in broccoli was carried out. In this study, higher AAO activity was observed in broccoli florets than stalks. During thermal treatments for 10 min, AAO in broccoli florets and stalks was stable until around 50 °C. A 10-min thermal treatment at 80 °C almost completely inactivated AAO in broccoli. AAO inactivation followed 1st order kinetics in the temperature range of 55 to 65 °C. Based on this study, a thermal treatment above 70 °C is recommended for crushed vegetable products to prevent oxidation of l -AA to DHAA, the onset of vitamin C degradation. Practical Application : The results reported in this study are applicable for both domestic and industrial processing of vegetables into products such as juices, soups, and purees. In this report, we have demonstrated that processing crushed broccoli in a temperature range of 30 to 60 °C could result in the conversion of l -ascorbic acid to dehydroascorbic (DHAA), a very important reaction in regard to vitamin C degradation because DHAA could be easily converted to other compounds that do not have the biological activity of vitamin C.     

加工处理方式对冲菜中硫代葡萄糖苷的影响

采用高效液相色谱法,对冲菜中主要的硫代葡萄糖苷种类和含量进行分析,并选择微波、热烫和蒸汽3种方法对冲菜进行处理,研究冲菜中硫代葡萄糖苷在不同处理过程中的热降解情况。结果表明：冲菜中含有两类硫代葡萄糖苷：脂肪族和吲哚族硫苷,其中含量较高的3种硫代葡萄糖苷分别为progoitrin、glucobrassicin和4-methoxyglucobrassicin;硫代葡萄糖苷在微波、热烫和蒸汽3种处理过程中的热降解均符合一级热降解动力学模型,其中glucotropaeolin的热稳定性均最差;对冲菜中总硫代葡萄糖苷的降解作用从大到小的顺序依次为：蒸汽、热烫、微波,但是微波处理最能促使对十字花科蔬菜中风味贡献最大的脂肪族硫苷的降解。     

Purification and Biochemical Characterization of Peroxidase Isolated from White Cabbage (Brassica Oleracea var. capitata f. alba)

Peroxidase enzyme was purified for the first time from white cabbage (Brassica oleracea var. capitata f. alba) in a single step using affinity chromatography and some biochemical characteristics of the purified enzyme were determined. The peroxidase was purified 24.7-fold with an overall recovery of 4.3% and a specific activity of 964.5. The molecular weight of the purified peroxidase was approximately 73.2 kDa as calculated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and it showed maximum activity at pH 6.5 and 30°C. For the guaiacol substrate, the K_M and V_max values were found as 3.19 mM and 0.2 EU/mL, respectively. Additionally, the IC₅₀ and K_i values were determined as 0.517 and 0.994 ± 0.453 mM, respectively, for 4-aminobenzohydrazide. 4-amino benzohydrazide showed non-competitive inhibition.     

Assessing the Impact of High-Pressure Processing on Selected Physical and Biochemical Attributes of White Cabbage (Brassica oleracea L. var. capitata alba)

The aim of this study was to investigate the effect of combined pressure/temperature treatments (200, 400 and 600 MPa, at 20 and 40 °C) on key physical and chemical characteristics of white cabbage (Brassica oleracea L. var. capitata alba). Thermal treatment (blanching) was also investigated and compared with high-pressure processing (HPP). HPP at 400 MPa and 20–40 °C caused significantly larger colour changes compared to any other pressure or thermal treatment. All pressure treatments induced a softening effect, whereas blanching did not significantly alter texture. Both blanching and pressure treatments resulted in a reduction in the levels of ascorbic acid, effect that was less pronounced for blanching and HPP at 600 MPa and 20–40 °C. HPP at 600 MPa resulted in significantly higher total phenol content, total antioxidant capacity and total isothiocyanate content compared to blanching. In summary, the colour and texture of white cabbage were better preserved by blanching. However, HPP at 600 MPa resulted in significantly higher levels of phytochemical compounds. The results of this study suggest that HPP may represent an attractive technology to process vegetable-based food products that better maintains important aspects related to the content of health-promoting compounds. This may be of particular relevance to the food industry sector involved in the development of convenient novel food products with excellent functional properties.     

Effects of harvest time and storage on dietary fibre components in various cultivars of white cabbage (Brassica oleracea var capitata)

The effect of harvest time and storage on dietary fibre content and composition was investigated in six cultivars of white cabbage (Brassica oleracea var capitata). Three cultivars were of early maturity type (SW Nordpol, Rolly and Balbro) and three of late maturity type (Predikant, Hanna and Lion). The average total dietary fibre (TDF) content was 241 g kg^?1 dry matter (DM) (CV = 13), of which approximately 25% was soluble (CV = 15). The main dietary fibre components were glucose (37%), uronic acid (32%), arabinose (12%) and galactose (8%) residues. Early cultivars generally had a lower TDF content than late maturity types, due to a lower amount of both insoluble (arabinose, galactose and glucose) and soluble (arabinose) polymers. An early cultivar, Rolly, had the highest solubility, 33%, versus 25 ± 4% for the other cultivars. The early cultivar SW Nordpol had a similar TDF content and proportion of soluble dietary fibre (SDF) to the late cultivar Hanna, but the dietary fibre composition was different, with the early cultivar having a lower proportion of arabinose residues. Storage for 6 weeks had minor effects on the dietary fibre. After further storage of the late maturity cultivars, there was an increase in insoluble dietary fibre (IDF) (glucose and uronic acid residues) and a decrease in SDF (arabinose and galactose residues). As a consequence the solubility of TDF decreased from 29 to 19% on average. Harvesting before physiological maturity was reached resulted in a somewhat lower content of TDF and IDF for two cultivars (Predikant and Hanna), while SDF was more or less unaffected for all cultivars. Long‐term storage had fewer effects on cabbage harvested prior to maturity than when harvested at the right physiological maturity. It is concluded that the observed differences between cultivars and after long term storage are of such magnitude that they may affect nutritional properties of the dietary fibre. © 2002 Society of Chemical Industry     

Stability and antioxidative properties of acylated anthocyanins in three cultivars of red cabbage (Brassica oleracea L. var. capitata L. f. rubra)

BACKGROUND: Red cabbage is rich in acylated anthocyanins. The aim of the experiment has been to determine the stability of anthocyanins in extracts of red cabbage cultivars and examine their antioxidative properties. The (high‐performance liquid chromatographic) HPLC profile of anthocyanins characteristic of each red cabbage cultivar has also been determined. RESULTS: We have used three red cabbage cultivars: cv. Koda, Haco POL and Kissendrup SWE. The HPLC assays enabled us to distinguish nine anthocyanin compounds, which were all classified as cyanidin derivatives. These compounds occurred in different proportions in the three culitvars of red cabbage. The differences were observed in the degradation index of anthocyanins in extracts from the red cabbage cultivars examined, both stored at + 2 °C and frozen. The highest trolox equivalent antioxidant capacity (TEAC) was attained for anthocyanins from cv. Haco POL red cabbage, whereas the lowest value was determined for cv. Koda. CONCLUSION: There were differences in the stability and antioxidative properties of anthocyanin compounds in red cabbage extracts among the cultivars evaluated (Koda, Haco POL and Kissendrup SWE). The highest stability and strongest antioxidative properties were assigned to anthocyanins in extracts from cv. Haco POL. The HPLC profiles imply differences in proportions of anthocyanin compounds present in the three red cabbage cultivars. Copyright © 2009 Society of Chemical Industry     

Effect of nitrogen and sulfur fertilization on glucosinolates in the leaves and roots of broccoli sprouts (Brassica oleracea var. italica)

Broccoli (Brassica oleracea L. var. italica cv. Marathon) sprouts are a rich source of glucosinolates, particularly 4‐methylsulfinylbutyl glucosinolate (glucoraphanin), the precursor of the chemoprotective isothiocyanate, sulforaphane. Sulfur and nitrogen fertilization have been shown to influence the pattern and levels of glucosinolates in mature broccoli, but little information is available on the fertilization of sprouts, a transient stage of broccoli growth, which have been recommended for salads. Therefore, an experiment was set up to evaluate the effect of N and S fertilization on the glucosinolate content of the aerial part and roots of broccoli sprouts. Nitrogen was tested at 0, 45.5, 91.0 mg L^?1 and sulfur at 0, 14.6 and 29.2 mg L^?1. The results showed that total glucosinolates in the aerial part were significantly higher (P < 0.001) than in the roots. The major glucosinolates in the aerial part were 4‐methylsulfinylbutyl and 3‐methylsulfinylpropyl whereas in the roots they were 2‐phenylethyl and 4‐methylthiobutyl. Fertilization of broccoli sprouts had a significant (P < 0.001) detrimental effect on the levels of aliphatic glucosinolates whereas the opposite was noted for indole and aromatic glucosinolates, for some of the fertilization combinations tested. Overall, the results indicate that broccoli sprouts do not benefit from fertilization. Copyright © 2006 Society of Chemical Industry     

乳酸菌发酵对雪里蕻挥发性物质及品质的影响

为研究菌种强化发酵对雪里蕻品质的影响,采用接种肠膜明串珠菌(Leuconostoc mesenteroides)、植物乳杆菌(Lactobacillus plantarum)、混合乳酸菌(肠膜明串珠菌和植物乳杆菌)发酵雪里蕻与传统自然发酵进行比较,通过感官评定及理化指标测定对发酵后雪里蕻品质进行分析,同时采用蒸馏萃取法提取挥发性物质,利用气相色谱-质谱(GC-MS)仪进行分析。结果表明:植物乳杆菌和肠膜明串珠菌强化发酵处理组优于自然发酵组;其中以植物乳杆菌处理组产生醛、酯类相对含量最高,挥发性物质总相对含量最高,VC损失最少,降低盐含量能力最佳,即植物乳杆菌发酵雪里蕻品质优于其他处理组。     

Total Phenolics,Carotenoids, Ascorbic Acid,and Antioxidant Properties of Fresh‐cut Mango (Mangifera indica L., cv. Tommy Atkin) as Affected by Infrared Heat Treatment

Abstract: Mango (Mangifera indica L.) is a major tropical fruit that has not been exploited for fresh‐cut or minimally processed products on a scale similar to apples, pineapples, or melons. The objective of this study was to investigate the effect of infrared (IR) treatment on total phenolics, carotenoids, ascorbic acid, and antioxidant properties of fresh‐cut cubes from ‘Tommy Atkin’ mangoes. Mango cubes were IR treated (5, 10, 15 min) and evaluated at 4‐d intervals during 16‐d storage at 4 ± 1 °C. Total phenolics, carotenoids, and ascorbic acid content in fresh‐cut control mango cubes were 43.33, 1.37, and 15.97 mg/100 g FW, respectively. IR treatments increased total phenolics (59.23 to 71.16 mg/100 g FW) and decreased ascorbic acid (12.14 to 15.38 mg/100 g, FW). Total carotenoids showed a mixed trend (1.13 to 1.66 mg/100 g, FW). The IR treatment showed a significant positive impact on antioxidant properties (μM TE/100 g, FW) of mango cubes, as assayed by ABTS (261.5 compared with 338.0 to 416.4), DPPH (270.5 compared with 289.4 to 360.5), and ORAC (6686 compared with 8450 to 12230). Total phenolics, carotenoids, ascorbic acid, and antioxidant capacity decreased over 16‐d storage. However, IR treated samples had consistently higher ABTS, DPPH, and total phenolics during storage. It was demonstrated that IR treatment can be effectively used in improving antioxidant properties of fresh‐cut mangoes with minimal effect on the visual appearance. Practical Application: Various methods/treatments are in use for extending the quality of fresh‐cut fruits, including mild heat treatment. This study explored the application of infrared (IR) heat for processing fresh‐cut mango cubes and evaluated its effect on vitamin C and antioxidant capacity during 16‐d storage. This is the first study reporting on the use of IR heat in fresh‐cut fruits. IR treatment was shown to be effective in retaining antioxidant properties of fresh‐cut mango cubes with minimal effect on the visual appearance.     

温度、机械伤和采收期对小白菜的采后生理的影响

研究结果表明 ,1℃低温能抑制小白菜的呼吸速率、乙烯生物合成、抗坏血酸氧化和贮藏中的失水。机械损伤明显提高了呼吸速率 ,乙烯释放 ,加速抗坏血酸含量的下降和提高失重率。采收迟的 (相对菜龄大的 )较采收早 (相对菜龄小的 )的呼吸速率低 ,抗坏血酸含量高且下降缓慢 ,失重率较低。因此为延长保鲜期 ,小白菜应在菜龄较大 (7～ 8片真叶期 )时采收 ,在较低温度 (1℃ )下贮藏 ,并尽量避免或减少采收及贮运过程中的机械伤。     

Lactobacillus Fermentum发酵降酸对三华李汁品质的影响

本文分析了三华李汁发酵乳杆菌发酵降酸期间乳酸菌活菌数、糖组分、有机酸、p H、可滴定酸、总酚、抗氧化活性、花色苷、色泽的变化规律。结果表明,在30℃的条件下,发酵乳杆菌缓慢生长,发酵6 d后,菌种数量趋于稳定;发酵期间,菌株对糖的利用较缓慢,仅利用少量的葡萄糖维持代谢生长,而对苹果酸的消耗较快。随着苹果酸的大量消耗以及少量乳酸的生成,三华李汁的p H值快速上升,可滴定酸含量迅速下降;发酵8 d后,菌种数量由初始的7.01 log CFU/m L增加到7.91 log CFU/m L,苹果酸被完全消耗,葡萄糖保留73.82%,果糖保留97.7%,p H值上升了0.38,可滴定含量下降了43.7%,总酚保留82.23%,抗氧化活性(ORAC值)升高了14.90%,花色苷保留50%以上,三华李汁的色泽变化不显著(p0.05)。因此,利用乳酸菌发酵三华李汁,不仅能够降低三华李汁酸度,而且很好地保留了三华李本身的营养成分。     

Monitoring colour,volatiles in the headspace and enzyme activity to assess the quality of broccoli florets (Brassica oleracea L. italica cv. Bellstar and Legacy) during postharvest storage

The research objective was to study whether volatile organic compounds released in the headspace could be used to assess the broccoli quality (Brassica oleracea L. italica cv. Bellstar and Legacy) during postharvest storage (23 °C for 7 days) and correlated with colour change and the activity of peroxidase/POD, ascorbic acid oxidase/AAO and lipoxygenase/LOX. Volatile organic compounds were monitored using PTR‐MS. Methanol had the highest concentration compared with other volatiles released in the headspace that significantly increased during senescence. The methanol concentration was approximately 500 ppbv before the broccoli colour began to change from green to yellow. The concentration of methanol in the headspace increased to 1000–1100 ppbv for Bellstar and Legacy when the colour became yellowish. LOX had high correlation (0.91 and 0.83 for Bellstar and Legacy, respectively) with volatiles for both cultivars, but not for POD. Methanol production is proposed as the best volatile marker to assess the broccoli quality.     

Effect of Germination,under Different Environmental Conditions,on Saponins,Phytic Acid and Tannins in Lentils (Lens culinaris)

The effect of germination conditions on some antinutrients of Lens culinaris var Magda 20 seeds were studied. The seeds were germinated at 20°C under variable conditions of time, water and light. Quantitative analyses of the soyasapogenols, inositol phosphates and tannins were carried out by capillary gas chromatography, high-performance liquid chromatography and spectrophotometric techniques respectively. Germinated seeds at day 6 contained higher levels soyasapogenol B than the controls, whereas in general the tannin content was reduced. Total phytic acid amounts did not decrease after 3 days of germination but was greatly reduced after 6 days. This work shows that the optimal conditions to reduce some antinutritional factors (tannins and phytic acid) in lentils were 6 days of seed germination in dark and with alternate watering. Therefore, germination conditions offer a good opportunity to improve the nutritional quality of lentils. © 1997 SCI.     

茶饼病侵染对茶树游离氨基酸组分及含量的影响

为揭示茶饼病菌对茶树叶片中游离氨基酸组分及其含量的影响,以3个不同抗性品种茶树的病、健叶为试验材料,利用高效液相色谱法(HPLC)检测不同抗性品种茶树未感病和感病后鲜叶中氨基酸的组分和含量。结果表明:不同抗性品种未感病叶片中游离氨基酸的的种类和含量有差异,茶氨酸含量最高,其次是γ-氨基丁酸、蛋氨酸、胱氨酸;感病后氨基酸总量上升,高抗品种紫娟叶片中游离氨基酸的种类减少,含量下降,仅γ-氨基丁酸含量增加;中抗品种云抗10号叶片中游离氨基酸的种类增加,含量均增加;感病品种佛香1号叶片中游离氨基酸的种类不变,γ-氨基丁酸、茶氨酸、赖氨酸、色氨酸、精氨酸5种游离氨基酸的含量增加,其余氨基酸的含量下降,因而可以以此分析氨基酸与茶树抗病性的关系。本研究结果可为从生理生化角度探讨茶饼病致病机理提供基础数据。