水肥处理对辣椒保护地土壤pH值的影响

探讨辣椒保护地的水肥耦合效应,采用二次回归正交旋转组合设计,建立了灌水定额、氮肥和磷肥对辣椒保护地土壤pH值影响的数学模型。通过模型分析得出:在辣椒保护地土壤养分含量高和施肥量大的条件下,灌水定额、施氮和施磷对辣椒保护地土壤pH值影响的大小顺序为:灌水>施氮>施磷。大量施用氮肥可使土壤酸化,灌水和高量施磷可减弱酸化效应,灌水与施氮、施氮与高量施磷对土壤pH值表现为拮抗作用。维持保护地土壤pH值种植前后稳定的水肥措施:灌水定额为170.71 m3/(hm2.次),施氮量为235.98 kg/hm2,施P2O5为239.38 kg/hm2。合理的施肥和灌水,可以控制土壤的酸化。     

Effects of ozone and chlorine postharvest treatments on quality of fresh‐cut red bell peppers

The effects of chlorine (200 μL L^?1), ozonated water (1 μL L^?1) and gaseous ozone (0.7 μL L^?1) on physicochemical attributes and microbial quality of minimally processed red bell peppers were studied. In all the experiments, O₂ continuously decreased and CO₂ concentration increased, the pH augmented and a significant softening was observed in all the fruits. By day 14, L* values decreased in all the fruits, with the greatest changes found in the chlorinated samples (approximately 12 units). Peppers treated with the aqueous solutions showed greater changes in the quality attributes with increasing washing times and especially when chlorine was used. The exposure for three min to gaseous O₃ reduced the mesophiles, psychrotrophes and fungal populations of the fresh‐cut peppers in 2.5, 3.3 and 1.8 log units, respectively. Combined with modified atmosphere, this could be an appropriate method to maintain the quality and extend the storage period of minimally processed red bell peppers.     

Leaf-to-Whole Plant Spread Bioassay for Pepper and Ralstonia solanacearum Interaction Determines Inheritance of Resistance to Bacterial Wilt for Further Breeding

Bacterial wilt (BW) disease from Ralstonia solanacearum is a serious disease and causes severe yield losses in chili peppers worldwide. Resistant cultivar breeding is the most effective in controlling BW. Thus, a simple and reliable evaluation method is required to assess disease severity and to investigate the inheritance of resistance for further breeding programs. Here, we developed a reliable leaf-to-whole plant spread bioassay for evaluating BW disease and then, using this, determined the inheritance of resistance to R. solanacearum in peppers. Capsicum annuum ‘MC4′ displayed a completely resistant response with fewer disease symptoms, a low level of bacterial cell growth, and significant up-regulations of defense genes in infected leaves compared to those in susceptible ‘Subicho’. We also observed the spreading of wilt symptoms from the leaves to the whole susceptible plant, which denotes the normal BW wilt symptoms, similar to the drenching method. Through this, we optimized the evaluation method of the resistance to BW. Additionally, we performed genetic analysis for resistance inheritance. The parents, F₁ and 90 F₂ progenies, were evaluated, and the two major complementary genes involved in the BW resistance trait were confirmed. These could provide an accurate evaluation to improve resistant pepper breeding efficiency against BW.     

Pungency threshold of capsaicin produced by in vitro culture of placental tissues of capsicum frutescens mill.

Production of capsaicin in free and immobilized placenta was compared in order to assess their capsaicin production ability. In immobilized placenta, maximum accumulation of capsaicin was on the 14th day of culture with a production of 2045 ug/culture, whereas in free placenta, the accumulation reached maximum on the 7th day (2050ug/culture). It was found that there was no significant difference between free and immobilized placenta in terms of capsaicin production, suggesting that immobilization is not necessary to enhance capsaicin accumulation in piacentai tissue. Pungency threshold of capsaicin produced in in vitro grown free piacentai tissues of Capsicum frutescens was done by Scoville heat units (SHU) method. Pungency analysis of capsaicin produced in free piacentai tissue showed that on day zero, pungency of tissue culture produced capsaicin (0.2267x10⁵ SHU) was comparable to standard natural capsaicin (0.222×10⁵ SHU), while on the 3rd day pungency of tissue culture produced capsaicin (0.3639×10⁵ SHU) was slightly lower than standard natural capsaicin (0.4415×10⁵ SHU).     

辣椒红色素纯化方法的研究

以辣椒油树脂为原料,重点研究了其纯化工艺.结果显示:用石油醚和pH10左右、浓度40%的丙酮溶液的混合液对辣椒油树脂进行萃取,萃取次数达到5次以上,即可得到较为优良的辣椒红色素产品.同时此法能有效地利用辣椒素成分,提高辣椒的利用率.     

陇东地区干红辣椒中辣椒红素的提取工艺研究

辣椒红素是一种重要的天然红色素,可从干红辣椒中提取得到。用浓度15％的氢氧化钠溶液除辣,采用不同有机溶剂对辣椒红素的提取工艺进行了比较研究。分别考察了丙酮、正己烷、乙酸乙酯以及乙酸乙酯与丙酮的混合溶剂对辣椒红素提取的影响,实验结果表明：正己烷为比较好的提取溶剂,在温度为80℃时提取4 h,可以从陇东地区辣椒中得到高产率、高色价、无异味的辣椒红素。     

辣椒的研究及开发现状

我国有丰富的辣椒资源，辣椒产量居世界第一，辣椒产品的生产正向多元化发展。辣椒加工不仅有传统的调味品生产，还包括了具有更高经济效益和社会效益的辣椒红色素、辣椒碱、辣椒籽油的开发，实现了辣椒的综合利用、变废为宝，同时更提高了辣椒本身的价值。概述了辣椒目前的研究开发状况，介绍了当今辣椒调味品的生产以及辣椒红色素、辣椒碱、辣椒籽油、辣椒中天然防腐剂和抗氧化物研究方面的成果和信息。     

辣椒酱防腐剂的研制

针对辣椒酱开盖后在食用期间容易起霉、变坏的问题进行了研究,并从中分离出了三株细菌、三株霉菌,针对这些微生物进行了有效的抑菌实验,并开发出了相应的防腐剂,添加了0.05%防腐剂的辣椒酱在开盖后室温下放置了25d才开始发霉。     

关于辣椒产品开发的几点构想

辣椒中具有保健功能的生理活性成分是辣椒产品开发的重要资源。目前我国辣椒产品还基本停留在传统的工艺和产品上，辣椒产品从产品形式、食用状态、感官质量、产品形象、食用美感在内的商品全方位深层次提升不足，成为制约辣椒产业产品层次提升的瓶颈。运用体验经济理念，通过辣椒调味品的精品化，是实现辣椒产业增值重要途径。     

Effect of Capsicum annuum (Red Sweet and Cayenne) and Piper nigrum (Black and White) Pepper Powders on the Shelf Life of Fresh Pork Sausages Packaged in Modified Atmosphere

ABSTRACT Capsicum annuum (red sweet and hot cayenne) and Piper nigrum (black and white) pepper powders were evaluated for inhibition of oxidative reactions and extension of the shelf life of fresh pork sausages packaged in a modified atmosphere. Sausages containing either red sweet pepper or cayenne pepper (0.1%, 0.5%, or 2%) or black or white pepper (0.1%, 0.5%, or 1%) were packaged in a modified atmosphere of 80% O₂+ 20% CO₂, stored for 16 d in the dark at 2 °C, and analyzed each 4 d for pH, CIE L*, a*, and b*, 2‐thiobarbituric acid‐reactive substances (TBARS), psychrotrophic aerobes, sensory discoloration, and off‐odor. Results demonstrated that Capsicum peppers (sweet red and hot cayenne) enhanced red color but failed to prevent discoloration, whereas they were very effective in inhibiting lipid oxidation, chiefly at the highest concentration used (2%), which resulted in a delay of off‐odor formation. Piper peppers (black and white) significantly delayed discoloration with small modification of sausage color; furthermore, they also inhibited lipid oxidation, which led to a delay of off‐odor formation, particularly in the form of black pepper. Besides this, all those spices inhibited microbial growth when added at the highest concentration (1%Piper and 2%Capsicum).