Phenolics and antioxidative activities in narrow-leafed lupins (Lupinus angustifolius L.)

Eight lupin (Lupinus angustifolius L.) genotypes grown at four locations in south central Alberta in 2004 were evaluated for variability in phenolic constituents and antioxidant activity measured by a photochemiluminescence assay. Genotype was the main source of variation for content of phenolic compounds and antioxidant activities. Phenolic compounds in genotypes varied minimally from 11.9 to 14.7 mg catechin equivalent and 4.15 to 4.95 mg rutin equivalent g(-1) lupin for total phenolic and flavonoid contents, respectively. Lupin genotypes exhibited weak antioxidant activity based on water-soluble substances (ACW) of 0.54 to 1.07 micromole Trolox equivalent antioxidant capacities (TEAC)/g with lag time ranging from 70 to 153 s and an antioxidant index of 6.7 to 14.5 and 1.9 to 3.3 micromole TEAC/g based on measurements of lipid-soluble substances (ACL). Antioxidant activity of lupin genotypes was not related to phenolic contents of seeds.     

Phenolics and Antioxidative Activities in Narrow-Leafed Lupins (Lupinus angustifolius L.)

Eight lupin (Lupinus angustifolius L.) genotypes grown at four locations in south central Alberta in 2004 were evaluated for variability in phenolic constituents and antioxidant activity measured by a photochemiluminescence assay. Genotype was the main source of variation for content of phenolic compounds and antioxidant activities. Phenolic compounds in genotypes varied minimally from 11.9 to 14.7 mg catechin equivalent and 4.15 to 4.95 mg rutin equivalent g⁻¹ lupin for total phenolic and flavonoid contents, respectively. Lupin genotypes exhibited weak antioxidant activity based on water–soluble substances (ACW) of 0.54 to 1.07 μmole Trolox equivalent antioxidant capacities (TEAC)/g with lag time ranging from 70 to 153 s and an antioxidant index of 6.7 to 14.5 and 1.9 to 3.3 μmole TEAC/g based on measurements of lipid-soluble substances (ACL). Antioxidant activity of lupin genotypes was not related to phenolic contents of seeds.     

Antioxidant activity and phenolic content of chestnut (Castanea sativa) shell and eucalyptus (Eucalyptus globulus) bark extracts

Chestnut (Castanea sativa) shell and eucalyptus (Eucalyptus globulus) bark, waste products of the food and wood industries, respectively, were analysed as potential sources of antioxidant compounds. The extraction yield, the antioxidant activity and total phenols content of the extracts were greater in chestnut shell than in eucalyptus bark for most of the extraction conditions essayed. Extraction of chestnut shell with a 2.5% Na₂SO₃ aqueous solution led to the highest extraction yield, 25.6%, total phenols, 13.4 g gallic acid equivalent/100 g oven-dried shell, and FRAP antioxidant activity, 80.7 mmol ascorbic acid equivalent/100 g oven-dried shell. Extraction with methanol:water (50:50, v/v) provided the best results for eucalyptus bark. The antioxidant activity and the total phenols content of the extracts had a positive linear correlation. FTIR spectroscopy confirmed the higher content of phenolic compounds in chestnut shell extracts compared to eucalyptus bark extracts. Chestnut shell extracts were characterized by the presence of high molecular weight species whereas lower molecular weight species were predominant in eucalyptus bark extracts.     

The Phenolic Contents and Antioxidant Activities of Infusions of <Emphasis Type="Italic">Sambucus nigra</Emphasis> L.

The aim of this work was to evaluate the antioxidant potential of teas prepared from twenty-four commercially available berries and flowers of Sambucus nigra L. in relation to their phenolic profile, as reflected by the most representative phenolic acids (caffeic, chlorogenic, p-coumaric, ferulic, gallic and syringic acids); flavonols (quercetin, kaempferol, myricetin and rutin); and total phenolic (TPC), phenolic acid (TAC) and flavonoid (TFC) contents. The infusions prepared from elderflowers contained more abundant phenolic compounds than the elderberry infusions. The TPC of these infusions ranged from 19.81 to 23.90 mg of gallic acid equivalents/g dry weight of sample (GAE/g DW) for elderberries and from 15.23 to 35.57 mg GAE/g DW for elderflowers, whereas the TFC ranged from 2.60 to 4.49 mg of rutin equivalents/g dry weight of sample (RUTE/g DW) in elderberry infusions and from 5.27 to 13.19 mg RUTE/g DW in elderflower infusions. Among the phenolic compounds quantified in this study, quercetin (2.07–9.48 mg/g DW) and myricetin (1.17–9.62 mg/g DW) had the highest concentrations in the teas prepared from berries and flowers, respectively. Moreover, the antioxidant potential of elder infusions assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and ferric reducing antioxidant power (FRAP) assays revealed that the teas prepared from flowers had higher mean DPPH and FRAP activities than the teas prepared from berries. Therefore, elder beverages could be important dietary sources of natural antioxidants that contribute to the prevention of diseases caused by oxidative stress.     

Effect of sucrose on antioxidant activities and other health-related micronutrients in gamma-aminobutyric acid (GABA)-enriched sprouting Southern Vietnam brown rice

Improving the nutritional quality of germinated brown rice (GBR) is important for the population consuming rice as part of the daily diet to offer health benefits. In this study, a set of popularly grown 79 rice varieties in Southern Vietnam was evaluated to identify the potential materials for producing gamma-aminobutyric acid (GABA)-enriched GBR. Enhancing antioxidant components, antioxidant activities, and other health-promoting micronutrients by sucrose treatment were also investigated in both white and red GBR. The results indicated that OM457 (white rice) and TN11 (red rice)-derived GBR had the highest GABA content of 105.68 mg GABA/100 g F.W and 47.68 mg GABA/100 g F.W among investigated rice varieties, respectively. Sucrose at 50 mM, in general, boosted total phenolic compounds, total flavonoids, anthocyanin content, thereby increasing antioxidant activities in both these GBR. Moreover, GC-MS-based metabolomic analysis indicated that GABA accumulation under sucrose treatment was rice pericarp/variety-specific. Also, sucrose stimulated the accumulation of other health-benefiting metabolites and free sugars. Altogether, the results in this study indicate that sucrose is an effective elicitor for improving the nutritional value in GBR, facilitating for production of ready-to-eat GBR with health-promoting benefits.     

黔引迷迭香主要酚类成分分析及抗氧化活性比较

采用高效液相色谱法（HPLC）对 4 种黔引迷迭香的多酚成分进行定性和定量分析,并利用 DPPH、ABTS自由基清除能力和铁离子还原能力（FRAP）3 种方法评价多酚成分的抗氧化能力。结果显示 4 种材料均富含类黄酮、酚酸和二萜酚等多酚类化合物,总酚含量介于 4 345.5~5 673.0 mg/100 g 。其中槲皮素、迷迭香酸、阿魏酸、绿原酸和鼠尾草酸是迷迭香最主要的酚类物质。黔引迷迭香 4 号的抗氧化活性最高,利用 DPPH、ABTS 和 FRAP等 3 种方法检测的结果依次为 184.4、290.0、155.6 μmol/g。相关性分析表明,总酚与总抗氧化活性能力显著相关,迷迭香酸对总抗氧化活性能力贡献最大,其次为鼠尾草酸、槲皮素和水杨酸。本研究对于了解黔引迷迭香抗氧化活性成分,以及资源的进一步开发利用具有重要指导意义。     

Fate of polyphenols and antioxidant activity of barley throughout malting and brewing

Phenolic contents of barley and malt extracts and their corresponding antioxidant activities were investigated using a chromatographic online antioxidant detection system. Ethyl acetate extracts of barley and malt were separated using reverse phase HPLC and compounds eluting from the column were submitted to two UV–visible detections: one for the phenolic compounds; and the other for the reduced form of the radical cation 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^•+) after the compounds were allowed to react online with it. Prodelphinidin B3 and procyanidin B3 were identified as two major contributors in the antioxidant activity of barley, in addition to catechin. Malting had a dramatic impact on these three compounds by resulting in a sharp decrease in their detected amounts and the associated antioxidant activities. Two other antioxidants, ferulic and sinapic acids, showed a better ability to withstand not only malting but also brewing steps. As for the overall phenolic content and antioxidant capacity, the study showed that malting allowed a better release and/or extraction of phenolic compounds, while the first brewing step caused the most significant damage by drastically decreasing the total polyphenols and their activity. Hopping however did not significantly affect neither the phenolic content nor the antioxidant activity.     

Phenolic compounds in raw and cooked rice (Oryza sativa L.) and their inhibitory effect on the activity of angiotensin I-converting enzyme

Whole rice has been widely studied due to the abundance of bioactive compounds in its pericarp. Some of the beneficial effects of these compounds on human health have been attributed to their antioxidant and other biological activities, such as enzyme inhibition. In this work, we evaluated the contents of total, soluble and insoluble phenolic compounds of 6 red and 10 non-pigmented genotypes of whole rice as well as their inhibitory effect on the activity of angiotensin I-converting enzyme (ACE). The effects of cooking on phenolics and their inhibitory activities were also investigated. Red genotypes showed high content of phenolics, mainly soluble compounds, at an average of 409.7 mg ferulic acid eq./100 g, whereas overall lower average levels (99.4 mg ferulic acid eq./100 g) at an approximate soluble/insoluble compound ratio of 1:1 were observed in non-pigmented rice. Pigmented rice displayed a greater inhibitory effect on ACE than non-pigmented rice. In fact, a significant correlation between the content of soluble phenolics and ACE inhibition was observed (r = 0.8985, p < 0.05). In addition to significantly reducing the levels of total phenolics and ACE inhibition, cooking altered the soluble/insoluble compound ratio, especially among red rice genotypes.     

Identification and quantification of phenolic acids and anthocyanins as antioxidants in bran,embryo and endosperm of white,red and black rice kernels (Oryza sativa L.)

Whole rice grain comprising endosperm, embryo (or germ), and bran has potential beneficial health effects in addition to provision of nutrients. The distribution of phenolic acids and anthocyanins in endosperm, embryo, and bran of white, red, and black rice grains was investigated in this study. The total phenolic content (TPC) was highest in the bran, averaging 7.35 mg GAE/g and contributing 60%, 86% and 84% of phenolics in white, red and black rice. The average TPC of the embryo and endosperm were 2.79 and 0.11 mg GAE/g accounting for 17% and 23%, 4% and 10% and 7% and 9% in white, red and black rice, respectively. The antioxidant capacity determined using DPPH and ORAC displayed a trend similar to TPC. Free/conjugated phenolic acids in white, red and black rice bran accounted for 41%, 65% and 85% of total acids. Bound phenolic acids in rice bran accounted for 90% of total acids in whole grain. Cis-p-coumaric was detected in bound form in bran while cis-sinapic acid was detected in the free/conjugated form in embryo and bran. Cyanidin-3-O-glucoside and peonidin-3-O-glucoside were identified mainly in black rice bran as the total anthocyanins. Cyanindin-3-O-rutinoside was also detected in black rice bran.     

Antioxidant activity of phenolic compounds obtained by autohydrolysis of corn residues

This study aimed to evaluate the effect of autohydrolysis temperature of corn residues in the antioxidant activity of the phenolic compounds extracted from the liquid phase. The treatments were carried out at 160, 180, 190 and 200 °C for 30 min in a pressurized batch reactor. Two different methods for phenolic compounds extraction from the autohydrolysis liquors were investigated. For that purpose, solvent extraction with ethyl acetate and acidic precipitation were performed for phenolic compounds recovery. These methods have been compared in terms of extraction yield, physicochemical properties of obtained polyphenols (characterization by Fourier Transform Infrared Spectroscopy, Thermogravimetric Analysis and Gel Permeation Chromatography), total phenolic content, total antioxidant capacity and Trolox equivalent antioxidant capacity (TEAC) values, measured in DPPH (2,2-diphenyl-1-picrylhydrazyl) test system. The maximum phenolic contents ranged from 6.04 mg GAE/100 mg extract in acidic precipitated samples to 16.45 mg GAE/100 mg extract in ethyl acetate soluble fractions. The results indicated that the ethyl acetate fractions possessed the highest antioxidant activity, reaching after 30-60 min the same capacity reported for the reference synthetic antioxidants (Trolox).     

Isolation and antioxidative properties of phenolics-saponins rich fraction from defatted rice bran

The study presents a protocol for the preparation of phenolics-saponins rich fraction (PSRF), a new active nutraceutical from defatted rice bran followed by the determination of its antioxidant properties. PSRF was prepared by employing a simple alcoholic fractionation procedure on the crude alcoholic extract (CAE) of defatted rice bran. PSRF was found to be significantly higher in the contents of total phenolic, saponin, and steroidal saponin than CAE and its counterpart, aqueous fraction (AqF) (p < 0.05). Except for iron chelating activity, PSRF exhibited notably higher activity than CAE and AqF in all antioxidant activity assays performed (p < 0.05). HPLC-DAD analysis revealed that PSRF contained substantially higher amounts of gallic acid, 4-hydroxybenzoic acid, caffeic acid, p-coumaric acid, and ferulic acid than CAE and AqF (p < 0.05). In conclusion, alcoholic fractionation of CAE simultaneously concentrated the phenolic compounds and saponins into PSRF, thus contributed to its higher antioxidant activity. Due to its elevated antioxidant properties, PSRF may be recommended for investigation as an active ingredient in the nutraceutical, functional food, and natural food preservative formulations. This is also the first report suggesting defatted rice bran as a potential and sustainable source of saponins.     

Effects of Roasting on Phenolic Composition and In vitro Antioxidant Capacity of Australian Grown Faba Beans (Vicia faba L.)

Faba bean phenolic compounds encompassed phenolic acids, flavonols, proanthocyanidins and anthocyanins. Roasting faba beans for 120 min decreased the total phenolic, flavonoid and proanthocyanidin contents by 42, 42 and 30 %, respectively. Roasting beans for 120 min decreased the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, total equivalent antioxidant capacity and ferric reducing antioxidant power by 48, 15 and 8 %, respectively. High performance liquid chromatography-post column derivatisation revealed the generation of new phenolic compounds as a result of roasting. Antioxidant mechanism of bean less-polar phenolic compounds was largely based on free radical scavenging activity. The bean phenolic compounds with reducing capability were heat stable. Roasted faba bean extracts (70 % acetone, v/v) were fractionated into relatively polar and non-polar fractions; the latter contributed the majority of the antioxidant capacity. The extracts from beans with different seed coat colours differed in their phenolic compositions, which suggest different levels of potential benefits to health. Although roasting initially lowers the bean antioxidant capacity, prolonged roasting at 150 °C for 60 min and longer causes generation of new phenolic compounds and an increased antioxidant capacity. The findings encourage a wider ultilisation of faba beans for human foods particularly in baked/roasted products.     

Effect of elevated carbon dioxide (CO2) on phenolic acids,flavonoids, tocopherols,tocotrienols, γ-oryzanol and antioxidant capacities of rice (Oryza sativa L.)

There have been no studies conducted with the objective of investigating the effect of elevated CO₂ concentrations ([CO₂]) on antioxidants in grains. Therefore, a two-year field experiment was conducted using open-top chambers with two levels of atmospheric CO₂ (375 and 550 μmol/mol) to evaluate their effects on rice grain antioxidants. Following exposure to high [CO₂], the total phenolic content of all rice milling fractions decreased (3%–18%), with the highest reduction in the brown rice for sinapic acid (167%), and in the white rice for p-hydroxybenzoic acid (100%). The total flavonoid content also decreased under elevated [CO₂] in all rice milling fractions (8%–14%), with apigenin (25%) being highly affected in the white rice, and tricin (12%) in the bran. The same trend was found for γ-oryzanol, with decreases of 35%, 32%, 25%, and 2% in the white rice, brown rice, husk, and bran, respectively. In the white and brown rices, tocopherols and tocotrienols were all lower under elevated [CO₂], with reductions larger for α-tocotrienol (69%), γ-tocotrienol (46%), and α-tocopherol (38%). Good correlations between antioxidant contents and DPPH radical scavenging capacities indicated that these decreases may be meaningful in the preventive ability of rice against free radical-mediated degenerative diseases.     

Polyphenol contents and antioxidant activities of five Indigofera species (Fabaceae) from Burkina Faso

Aqueous acetone extracts prepared from five Indigofera species of Burkina Faso, namely Indigofera colutea (Burm.) Murril., I. macrocalyx Guilld et Perr., I. nigritana Hook f., I. pulchra willd. and I. tinctoria L., were investigated for their phytochemical composition and their antioxidant activities. Standard methods and TLC were used to screen the phytochemical composition. The total phenolic and flavonoid content of extracts were assessed by Folin-Ciocalteu and AlCl3 methods, respectively. These extracts were also evaluated for their antioxidant potentials using ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonate) (ABTS) assays. Flavonoids, saponins, quinones, sterols/triterpenes and tannins were present in all these species except for I. pulchra where quinones were not found. Gallic acid, caffeic acid, rutin and myricetin in I. colutea; gallic acid, quercitrin, myricetin in I. tinctoria; galangin and myricetin in I. macrocalyx were identified by thin layer chromatography. Among these, I. colutea, I. tinctoria, I. nigritana and I. macrocalyx, which had the highest phenolic content, were also found to possess the best antioxidant activities. The results indicated a good correlation between antioxidant activities and total phenolic content (p<0.05 for FRAP/DPPH and DPPH/ABTS and p<0.01 for FRAP/ABTS). These plants represent promising sources of natural antioxidants and these findings give scientific bases to their ethnopharmacological uses.     

镍处理下水稻酚酸和酚多聚物含量的变化与白叶枯病诱导抗性的关系

 研究了镍处理下水稻叶片中总酚、酚酸、酚多聚物积累和细胞壁结合态过氧化物酶（POD）活性的变化。镍处理导致总酚含量显著上升,检测到10种可溶性酚酸和7种结合态酚酸。镍处理下可溶性绿原酸和水杨酸含量明显上升,而它们的结合态含量变化不明显;镍处理显著提高可溶性和结合态阿魏酸的含量,显著降低可溶性丁香酸和对 香豆酸的含量,却诱导其结合态含量增加。镍处理后酚多聚物明显积累,以阿魏酸和丁香醛为底物的细胞壁结合态POD的活性显著升高。这些结果结合以前的研究提示,酚酸和酚多聚物积累参与了镍诱导的水稻对白叶枯病的抗性。     

节水灌溉下南方双季稻区主栽机插水稻品种的光合特性和产量

为了比较不同品种在干湿交替条件下的品种特性,以11份水稻品种为材料,分析比较了水稻秧苗素质、光合特性、产量及产量构成因素的差异。研究结果表明：不同品种秧苗素质差异显著,主要以苗高、白根数、总根数差异较为明显,其中以24d61（A2）品种秧苗地上、地下部性状最佳,为最适宜机插品种。不同品种抽穗期光合特性有所差异,其中24d44（A 6）品种净光合速率最高,为27.01 μmol/(m ²·s),中早39（A7）品种气孔导度与蒸腾速率最高,分别为1.69 mmol/(m ²·s)和12.10 mmol/(m ²·s),中嘉糯（A1）品种胞间CO₂浓度显著高于其他品种,为376.09 μmol/(m ²·s)。不同品种产量及其构成因素显著,陆两优996（A10）品种株高、单株产量、结实率与每穗着粒数均为最高。抽穗期光合特性与产量构成各指标相关性分析表明,净光合速率与蒸腾速率、单株有效穗数、千粒重呈正相关,与胞间CO₂浓度与结实率呈显著负相关;单株产量与每穗着粒数、结实率呈显著正相关,与株高、千粒重呈正相关,与光合特性各指标呈负相关,但差异均未达到显著性。因此,本研究对节水灌溉条件下水稻机械化种植模式适宜品种的筛选有重要意义。     

基于主成分分析和聚类分析的不同水稻品种营养品质评价研究

为了评价不同颜色糙米品种的营养品质,以3个红米品种、8个黑米品种和8个普通糙米品种为材料,对其5项基本营养成分、13种矿质元素含量和9项活性物质含量等27项营养品质指标进行比较分析,并采用主成分分析和聚类分析对不同水稻品种进行营养品质评价。结果表明,不同品种稻米的总淀粉、膳食纤维和脂肪含量在较小范围内波动;有色米品种的矿质元素含量变化范围较大,普通糙米品种的变化范围较小;总酚、总黄酮、ABTS和DPPH抗氧化活性间存在极显著的相关性,其在有色米品种中的含量显著高于普通糙米品种,且大多数黑米品种的含量显著高于红米品种;总花色苷、矢车菊素-3-O-葡萄糖苷、芍药素-3-O-葡萄糖苷在黑米品种中含量比较高。对稻米基本营养成分和矿物质元素等指标进行主成分分析,提取了6个主成分,其累积方差贡献率达80%左右,可以较好反映稻米的营养品质。对19个水稻品种稻米的所有营养品质参数进行聚类分析,可以将水稻品种分为有色米类和普通糙米类;将所有品质指标分为五类,其两类主要是矿质元素,一类主要是活性物质,两类主要是基本营养成分。该研究结果可为稻米营养品质的评价提供科学依据,也可为生产功能性稻米新产品提供新思路。     

Alpha-amylase treatment increases extractable phenolics and antioxidant capacity of oat (Avena nuda L.) flour

In this work, α-amylase was used to treat oat flour with the intent to release phenolic compounds with known antioxidant properties. After methanol extraction, the amounts of nine beneficial phenolic compounds were measured using HPLC. The antioxidant activities of the extracts were assessed using 2,2′-azinobis (3- ethylbenzothiazoline-6-sulfonic acid) (ABTS)，2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and protein oxidative damage protection assays. Compared with heating-only treated oat flour, that treated with α-amylase showed significant increase of extractable total phenolic content (0.46–1.35 μmol gallic acid equivalents per gram oat), total antioxidant capacity, and an increased ability on the protection of protein from oxidative damage. Heating-only increased caffeic acid and vanillin content by 17 (0.03 vs 0.54 μg/g oat) and 1.8 (0.62 vs 1.11 μg/g oat) folds, but slightly increased the content of other phenols. Excluding heating effect, α-amylase treatment increased gallic acid content by 2.6 folds (0.38 vs 1.38 μg/g oat), caffeic acid content by 2.4 (0.54 vs 1.82 μg/g oat) folds, and other phenols by 1.0–1.8 folds. In conclusion, α-amylase treatment can yield oat products containing more extractable phenolic compounds with increased antioxidant capacity.     

Phytochemical Properties and Antioxidant Activities of Extracts from Wild Blueberries and Lingonberries

Among Vaccinium species, blueberries (Vaccinium myrtillus L.) and lingonberries (Vaccinium vitis-idaea) are popular in the human diet. In this study, total phenolic, total flavonoid and total monomeric anthocyanin contents in the ethanol-water extracts of blueberry and lingonberry fruits grown wild in the forests in the central region of Poland were assayed. Antioxidant activities of the extracts from each plant were also evaluated for scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and reducing power by cupric reducing antioxidant capacity (CUPRAC) method. Total phenolics in the blueberry extracts ranged from 4.58 to 5.28 mg GAE CE/g fw. The extracts from lingonberry fruits contained higher total contents of phenolic compounds (5.82–7.60 mg GAE/g fw) as well as total flavonoids (5.22–6.47 μmol CE/g fw) than those from blueberries (3.74–4.18 μmol CE/g fw). For the total monomeric anthocyanin contents, the blueberry extracts presented significantly higher values (3.01–3.93 mg cyanidin-3-glucoside (C3G) equivalent/g fw) in comparison to the lingonberry extracts (0.32–0.47). Blueberry extracts exhibited higher antioxidant activity measured by both assays in comparison to lingonberry extracts. Water extracts from fresh and dried fruits also exhibited significant antioxidant activities for both types of berries. Considering the health benefits that have been associated with polyphenolic consumption, these fruits could appear as a good source of this group of phytochemical compounds for their direct consumption or their use as ingredients for the design of new food products or food supplements.     

酸刺激和谷氨酸处理对不同粳稻品种稻谷γ-氨基丁酸积累的影响

以常优94 1、浙湖9423、R717、中超123、赚钱1号和日本晴6个粳稻品种为材料,比较研究了种子萌发时间、酸刺激和L 谷氨酸（L-Glu）浸泡处理对不同品种稻谷中GABA积累的影响。萌发活化4～6 d、pH 6.0缓冲液浸泡2 h及50 mmol/L的L Glu 浸泡12 h能显著促进萌发稻谷中GABA的积累,使萌发稻谷中GABA含量较萌发前增加0.8～5.9倍; 不同品种稻谷GABA初始含量不同,萌发活化、酸刺激和L-Glu浸泡处理对稻谷积累GABA的促进效应具有很大的品种差异。经处理后中超123和日本晴两个品种GABA含量高,分别达到1.1236 mg/g和0.9064 mg/g,是萌发前的5.6和22倍。