Identification of aroma components of Spanish ‘Verdejo’ wine

Aroma components of ine resulting from fermentation of grape must from the Verdejo cultivar ere isolated by continuous liquid-liquid extraction and further fractionation on a silica gel column. One hundred and thirty-to substances, including alcohols, esters, carbonyl compounds, terpenes, acids and sulphur compounds, ere identified by using GC-MS; some had not been previously detected in ines. Data are given hich could lead to the characterisation of the Verdejo cultivar and the effect of the elaboration of young ines. The sensory contribution of some volatile compounds to the flavour of Verdejo ine is also studied.     

Lowland rice response to potassium fertilization and its effect on N and P uptake

Not much is known about the response of lowland rice to K fertilization under Brazilian conditions. A field experiment was conducted during four consecutive years to determine the response of three lowland rice (Oryza sativa L.) cultivars to K fertilization on a Low Humic Gley soil. In the first two years, K was broadcast at rates of 0, 42, 84, 126, and 168 kg K ha^–1. In the last two years K rates were reduced to 0, 25, 50, 75, and 100 kg K ha^–1 and applied in a band. Potassium significantly (P < 0.01) increased grain yields but the response varied from cultivar to cultivar and year to year. Yield responses to K fertilization were superimposed on a general trend of increasing grain yields across the four growing seasons. Mean grain yields increased 14.3% with broadcast application of K in the first two years and 10.4% with banded application of K in the last two years when compared to the control treatments. Extractable soil K increased with K application rate and decreased with soil depth. Potassium was rapidly removed from the soil and yearly broadcast or banded application of K can be expected to result in a significant increase in grain yield of lowland rice in these soils.     

Effect of potassic and phosphatic fertilizer type, fertilizer Cd concentration and zinc rate on cadmium uptake by potatoes

In some areas of southern Australia, cadmium (Cd) concentrations in excess of the Australian maximum permitted concentration (0.05 mg kg^–1 fresh weight) have been found in tubers of commercially grown potato (Solanum tuberosum L.) crops. Field experiments were therefore conducted in various regions of Australia to determine if Cd uptake by potatoes could be minimised by changes in either phosphorus (P), potassium (K) or zinc (Zn) fertilizer management.Changing the chemical form in which either P fertilizer (monoammonium phosphate, diammonium phosphate, single superphosphate and reactive rock phosphate) or K fertilizer (potassium chloride and potassium sulfate) were added to crops had little influence on tuber Cd concentrations. Fertilizer Cd concentrations also had little influence on tuber Cd concentrations, suggesting that residual Cd in the soil was a major contributor to Cd uptake by the crops on these soils.Addition of Zn at planting (up to 100 kg Zn ha^–1) significantly reduced tuber Cd concentrations at four of the five sites studied. However, the largest variation was between sites rather than between treatments, with site mean tuber Cd concentrations varying tenfold (from 0.018 to 0.177 mg Cd kg^–1 fresh weight). Factors associated with irrigation water quality at the sites, in particular the chloride concentration, appeared to dominate any effects of changing fertilizer type or Cd concentration.     

Comparison of aromatic and phenolic compounds in cherry wines with different cherry cultivars by HS‐SPME‐GC‐MS and HPLC

To compare the influence of cultivars on the production of aroma compounds and polyphenols, eight cherry varieties (six sweet and two sour) were fermented into cherry wines, and their compositions were analysed. Results showed that by headspace solid microextraction coupled to gas chromatography–mass spectrometry (HS‐SPME‐GC‐MS), a total of twenty‐first aromatic compounds, mostly consisting of esters, acids, terpenoids and C₁₃‐norisoprenoids, were identified, and eleven polyphenols including five anthocyanins and six phenolic acids were quantified using HPLC. May Duck and Early Richmond wines contained significantly higher levels of phenolic acids (>42 mg L^?1) that were associated with high contents of chlorogenic and neochlorogenic acids and also relatively high amounts of octanoic acid and β‐damascenone (odour activity values ≥1000). Hongdeng, Zhifuhong and Bing wines were characterised by higher concentrations of anthocyanins (>41 mg L^?1) and also relatively higher levels of isopentyl acetate. Lapins and Governer Wcod wines were distinguished by lower concentrations of polyphenols and relatively higher contents of ethyl 3‐methylbutanoate.     

Effects of Variety,Maturation and Growing Region on Chemical Properties,Fatty Acid and Sterol Compositions of Virgin Olive Oils

Chemical properties, fatty acid and sterol compositions of olive oils extracted from Gemlik and Halhal? varieties grown in Hatay and Mardin provinces in Turkey were investigated during four maturation stages. The olive oil samples were analyzed for their chemical properties such as free acidity, peroxide value, total carotenoid, total chlorophyll, total phenolic contents, antioxidant activity, fatty acid and sterol compositions. Chemical properties, fatty acids and sterol profiles of olive oil samples generally showed statistically significant differences depending on the varieties, maturation and growing areas (p < 0.05). As free fatty acid contents and total phenolic contents increased, total carotenoid and chlorophyll contents decreased throughout the maturity stages. Total carotenoid and chlorophyll contents of oil samples from Mardin were higher than those of Hatay. The total phenolic compounds of olive oil samples ranged from 20.62 in Gemlik to 525.22 mg GAE/kg oil in Halhal? from Hatay. In general, the phenolic contents and antioxidant activities of olive oil samples were positively associated. Oleic acid content was the highest 71.53 % in H1 samples in Hatay. Total sterol contents were 1194.33 mg/kg in Halhal? and 2008.66 mg/kg in Gemlik from Hatay. Stigmasterol contents of oils obtained from Hatay were lower than those of Mardin. Oleic acid, palmitic acid, β‐sitosterol, ?‐5‐avenasterol and campesterol contents fluctuated with maturation for each of variety from both growing regions. These results showed that the variety, growing area and maturation influence the chemical properties, fatty acid and sterol compositions.     

Variations of iridoid oleuropein in Italian olive varieties during growth and maturation

This research paper reports on the concentrations of oleuropein in fruits of seven Italian olive cultivars. These oleuropein levels, during fruit growth and maturation, were monitored by taking olive samples from the same olive trees grown in Middle Italy. A novel high‐resolution gas chromatography (HRGC) oleuropein quantification method and a new high‐performance liquid chromatography (HPLC) method were developed. The olive fruits showed high contents of oleuropein, which were greatly influenced by the olive cultivar (genetic store) factor. The stage of fruit growth and maturation was another factor strongly affecting the contents of iridoid oleuropein in olive drupes, whatever the olive cultivar considered. Green olives had much higher concentrations of this biofunctional glucoside, which decreased regularly during fruit growth and ripeness. No differences were observed between the two developed oleuropein quantification methods, which gave, for all the olive cultivars, average values of fruit oleuropein contents that were not statistically different. These two reliable repetitive methods, noticeably the HPLC one (which also showed a lower running time), could be used for routine determination of oleuropein in olive drupes. We observed that, in general, olive cultivars having high oleuropein concentrations in the fruits were also characterized by marked oleuropein contents in the leaves.     

Content of low molecular weight carbohydrates in vining peas (Pisum sativum) after blanching and freezing: effect of cultivar and cultivation conditions

The content of low molecular weight carbohydrates (LMWC, glucose, fructose, sucrose, raffinose, stachyose and verbascose) was investigated in 29 cultivars of vining peas after blanching and freezing. The peas were harvested at about the same degree of ripeness. There was a positive correlation between the amount of raffinose, stachyose and sorbitol, while a high content of verbascose only could be seen when there was a low content of these sugars. High concentrations of sucrose were generally associated with high concentrations of glucose and fructose. Samples from 1999 had a significantly (p < 0.001) higher content of raffinose, stachyose and sorbitol and lower of verbascose, probably because of the drier and warmer summer that year compared with 1998. Furthermore, medium and late maturing cultivars contained larger amounts of raffinose, stachyose and sorbitol than early cultivars, possibly due to the fact that these cultivars, to a greater extent, were exposed to a higher temperature and more intense sunlight for a longer time. Considerable differences in the content of LMWC could be seen both between the different cultivars and the various trials. Glucose and sucrose were generally similarly affected by cultivar and cultivation conditions, while cultivation conditions had a greater influence on the content of sorbitol and the raffinose family oligosaccharides (RFO; raffinose, stachyose, verbascose) in late‐maturing groups. It is concluded that many factors affect the content of LMWC in peas. However, as the content of RFO is comparatively small in vining peas, any nutritional significance of these sugars in the human colon is probably rather small. Copyright © 2004 Society of Chemical Industry     

不同品种甜樱桃中不同形态酚酸的比较及其抗氧化性分析

为研究不同品种对甜樱桃酚酸类物质及其抗氧化性的影响,本文采用超高效液相色谱-串联质谱法(UPLC-MS/MS)对5个不同品种甜樱桃,包括彩虹、艳阳、萨米脱、23-51和瓦列里中的游离型、游离酯型和结合型酚酸进行了测定和分析。结果表明,不同樱桃品种间酚酸含量差异较大,5个樱桃品种酚酸总量在115.96~704.94 mg/kg FW之间。其中瓦列里中酚酸总量最高,其次是萨米脱和23-51,艳阳和彩虹中酚酸总量最低。对于三种不同形态酚酸,游离型和游离酯型酚酸含量较高,而结合型酚酸含量较低。不同品种樱桃中的游离型酚酸以新绿原酸为主,可占游离型酚酸总量的90%以上;游离酯型酚酸和结合型酚酸均以咖啡酸含量最高,可占各自形态酚酸总量的50%以上。不同品种中瓦列里樱桃酚酸提取液的DPPH自由基清除能力和FRAP均最高,抗氧化性指标的测定结果与酚酸类物质含量呈现较高的一致性。偏最小二乘判别分析表明,新绿原酸和咖啡酸是区分五个樱桃品种贡献最大的物质(VIP得分>1),且这两个物质均在瓦列里中含量最高。甜樱桃酚酸含量与品种有关,并与其抗氧化特性相一致。     

干燥方式、储存温度和品种对玉米中伏马毒素B1的影响

伏马毒素B_1广泛存在于玉米中,是玉米及其制品质量安全的重要危害因子。选取23个玉米品种为研究对象,对不同干燥方式(烘干、晒干和晾干)和不同储藏温度(4、15、25℃、常温)对其中伏马毒素B_1的影响进行研究,结果表明:玉米进行烘干、晒干和晾干后放置3个月后,伏马毒素B_1含量为烘干晒干晾干,玉米水分含量与伏马毒素B_1含量显著相关(r=0.678);不同温度中放置3个月后,伏马毒素B_1含量由小到大为4℃15℃25℃室温;烘干、4℃储存玉米中伏马毒素B_1含量分别为0～1.39 mg/kg(平均值0.40 mg/kg)、0.08～1.60 mg/kg(平均值0.78 mg/kg),均低于美国FDA规定的最高限量(2 mg/kg);品种对玉米中伏马毒素B_1含量影响显著。烘干、4℃储存、选取高抗镰刀菌玉米品种可有效控制在储藏过程中伏马毒素B_1对玉米的污染。     

山东茶区与南方茶区不同茶树品种特性试验比较

在不同的地理环境和气候条件的影响下,同一茶树品种的一些植物特性与原产地发生了变化,造成茶叶营养成分含量的差异性。本文通过对不同茶树品种主茶区有代表性试验地调查研究分析,发现不同区域有明显的差异,茶叶品质也拥有了当地栽培的一些特殊性。