中国谷物醋的感官风味特征分析

为了分析中国谷物醋(Chinese cereal vinegars,CCV)的感官风味特征,收集了中国四大传统名醋产区山西、四川、福建和江苏的8个品牌,3种不同陈酿程度的食醋产品共24个,对它们的感官风味进行了分析和比较。结果表明,仅巧克力味、烘焙味、肉汤味等少数几种风味是这些CCV产品共有的,而其他一些风味,如胶水味、水果味和甘草味,为某些CCV产品所特有。研究还发现,陈酿对提升CCV的烘焙味和巧克力味起到了非常关键的作用,而原材料在某些产品风味,如甘草味的形成中可能起到了重要作用。

国际谷物供需形势及我国谷物发展对策

为应对在全球快速蔓延的粮食价格危机对本国的冲击,谷物出口国纷纷出台控制谷物出口政策,谷物进口国纷纷到国际市场抢购谷物;一些经济较贫困的国家因无力在国际市场抢购谷物,或无力通过财政补贴抑制国内谷物价格快速上涨,而诱发社会动荡。尽管我国受世界谷物价格危机的冲击不大,但潜在危机仍存在,还需采取强力措施。

Glycemic index of cereals and tubers produced in China

AIM： To determine the GI of some cereals and tubers produced in China in an effort to establish the database of glycemic index （GI） of Chinese food.METHODS： Food containing 50 g carbohydrate was consumed by 8-12 healthy adults after they have been fasted for 10 h and blood glucose was monitored for 2 h. Glucose was used as reference food. GI of food was calculated according to a standard method.RESULTS： GI of 9 types of sugar and 60 kinds of food were determined.CONCLUSION： Food GI is mainly determined by nature of carbohydrate and procession. Most of cereals and tubers produced in China have similar GI with their counterparts produced in other countries.

Extreme Flood Events over the Past 300 Years Inferred from Lake Sedimentary Grain Sizes in the Altay Mountains,Northwestern China

Understanding the temporal variations of extreme floods that occur in response to climate change is essential to anticipate the trends in flood magnitude and frequency in the context of global warming. However, long-term records of paleofloods in arid regions are scarce, thus preventing a thorough understanding of such events. In this study, a reconstruction of paleofloods over the past 300 years was conducted through an analysis of grain sizes from the sediments of Kanas Lake in the Altay Mountains of northwestern China. Results showed that grain parameters and frequency distributions can be used to infer possible abrupt environmental events within the lake sedimentary sequence, and two extreme flood events corresponding to ca. 1736–1765 AD and ca. 1890 AD were further identified based on canonical discriminant analysis(CDA) and coarse percentile versus median grain size(C-M) pattern analysis, both of which occurred during warmer and wetter climate conditions by referring to tree-ring records. These two flood events are also evidenced by lake sedimentary records in the Altay and Tianshan mountains. Furthermore, through a comparison with other records, the flood event from ca. 1736–1765 AD in the study region seems to have occurred in both the arid central Asia and the Alps in Europe, and thus may have been associated with changes in the North Atlantic Oscillation(NAO) index.

Impacts of Drought and Human Activity on Vegetation Growth in the Grain for Green Program Region,China

The Chinese government adopted six ecological restoration programs to improve its natural environments. Although these programs have proven successful in improving local environments, some studies have questioned their performance when regions suffer from drought. Whether we should consider the effects of drought on vegetation change in assessments of the benefits of ecological restoration programs is unclear. Therefore, taking the Grain for Green Program(GGP) region as a study area, we estimated vegetation growth in the region from 2000–2010 to clarify the trends in vegetation and their driving forces. Results showed that: 1) vegetation growth increased in the GGP region during 2000–2010, with 59.4% of the area showing an increase in the Normalized Difference Vegetation Index(NDVI). This confirmed the benefits of the ecological restoration program. 2) Drought can affect the vegetation change trend, but human activity plays a significant role in altering vegetation growth, and the slight downward trend in the NDVI was not consistent with the severity of the drought. Positive human activity led to increased NDVI in 89.13% of areas. Of these, 22.52% suffered drought, but positive human activity offset the damage in part. 3) Results of this research suggest that appropriate human activity can maximize the benefits of ecological restoration programs and minimize the effects of extreme weather. We therefore recommend incorporating eco-risk assessment and scientific management mechanisms in the design and management of ecosystem restoration programs.

Photosynthetic characteristics of intercropped winter wheat under limited supplemental irrigation in the semiarid northwestern China

A field experiment was conducted for intercropped winter wheat （Triticum aestivum） in 2002/2003 to evaluate the effects of limited supplemental irrigation on photosynthetic characteristics of intercropped winter wheat in semiarid environment. The result indicated that significances occurred in grain yield between the intercropped wheat treatments and sole wheat control （CKW）, and in yield between the irrigated intercropped wheat plots （WC2W, WC3W, WC5W） and not irrigated （WC1W） except for WC4W plots with nearly the same yield as WC1W. In comparison with CKW, 11.8%, 18.5%, 23.6%, 11.5%, and 30.7% of yield increase in the intercropped wheat plots were obtained in WCIW, WC2W, WC3W, WC4W, and WC5W respectively. Compared to the intercropped wheat plots without irrigation, yields in WC2W, WC3W, and WC5W were improved by 5.9%, 10.5%, and 16.9%, respectively. The dynamics of CGR and NAR in both intercropped （WC1W-WC5W） and solely cropped wheat （CKW） showed a type of ＂single peak＂ curves, with both the maximum CGR and NAR occurred during jointing to heading （14/4-6/5） of wheat. In addition, soil water potential （SWP） fluctuated as a function of the precipitation and limited supplemental irrigation.