催化式红外辐照改善樱桃番茄去皮效果及品质

为了探寻一种去皮效果好、产品品质破坏低和环境友好型的樱桃番茄去皮方法,该文采用催化式红外技术对樱桃番茄进行处理,研究了不同催化式红外条件对樱桃番茄去皮效果的影响,并与传统的去皮方式(热水和碱液去皮)和超声波去皮方式进行对比,比较其去皮效果、番茄红素含量、果肉色泽和质构等指标变化。结果表明:催化式红外在照射距离30cm和照射时间3min的条件下,樱桃番茄的去皮效果最佳;与传统的去皮方式相比,催化式红外的去皮效果显著提升(P0.05);并且经催化式红外去皮方法所得樱桃番茄的皮肉质量比仅为7.68%,显著降低了樱桃番茄的果肉损失(P0.05)。此外,催化式红外去皮很好地保持了去皮后番茄果肉形状的完整度,是一种去皮效果良好的环境友好型樱桃番茄去皮方式。     

Addition of Glucose Oxidase for the Improvement of Refrigerated Dough Quality

Refrigerated dough encompasses a wide range of products and is a popular choice for consumers. Two of the largest problems that occur during refrigerated dough storage are dough syruping and loss of dough strength. The goal of this study was to evaluate glucose oxidase as an additive to refrigerated dough with the purpose of maintaining dough strength and retarding dough syruping. Refrigerated dough was evaluated for the degree of dough syruping (DDS), dough strength, rheological characteristics, baking quality, and protein quality. The addition of glucose oxidase at 10 mg/kg was able to significantly (P < 0.05) reduce dough syruping and maintain the strength of the dough. Addition of glucose oxidase at 5 and 25 mg/kg was not able to reduce the level of dough syruping at a satisfactory level. Degradation of protein was found to occur during storage of refrigerated dough. DDS had a negative correlation (r = –0.60 to –0.94) to the level of polymeric proteins and a positive correlation (r = 0.60 to 0.98) to the low‐molecular‐weight proteins. Overall, glucose oxidase at 10 mg/kg can improve refrigerated dough quality by reducing dough syruping and maintaining dough strength.     

Refrigerated dough syruping in relation to the arabinoxylan population

Refrigerated doughs develop syruping upon prolonged storage. To assess the role of arabinoxylans (AX), in this phenomenon, the evolution of the AX population and syruping in refrigerated doughs during storage were studied. When doughs were kept at 6 degrees C for up to 34 days of storage, dough syruping increased from 0% (fresh dough) to 22% of dough weight, reaching a plateau after 16 days of storage. High-performance size exclusion chromatography and gas-liquid chromatography showed hydrolysis of water-unextractable AX in the refrigerated dough, resulting in increased levels of solubilized AX in the first 2 days of storage. Longer storage resulted in further degradation of solubilized and water-extractable AX. Increased syruping was accompanied by a decrease in farinograph dough consistency. The results support the hypothesis that loss of water-holding capacity due to degradation of AX by endogenous xylanases is responsible for dough syruping.     

Refrigerated Dough Quality of Hard Red Spring Wheat: Effect of Genotype and Environment on Dough Syruping and Arabinoxylan Production

Arabinoxylans (AX) are the main nonstarch polysaccharides found in wheat flour. Structural changes of AX in refrigerated dough are linked to deleterious effects on refrigerated dough quality during storage. The purpose of this research was to evaluate the effect of cultivar and growing environment on dough syruping during refrigerated storage in relation to apparent xylanase activity and AX chemistry in hard red spring (HRS) wheat. Eight HRS cultivars that were grown at six locations over two years in North Dakota were evaluated for dough syruping during 15 days of refrigerated storage. When compared with genotypic effect, growing environment had a greater impact on apparent xylanase activity and dough syruping; they were found to have significant associations by log‐linear regression analysis. Specifically, wheat samples produced in a dry environment had lower apparent xylanase activity and degree of dough syruping than those from a wet environment. Some HRS cultivars were identified to be consistently lower in apparent xylanase activity and dough syruping across all growing environments, indicating that those cultivars had more stability over growing environment than other cultivars. These results indicate that certain cultivars that are grown in relatively dry environments in North Dakota are more suitable for use in refrigerated dough formulations.     

不同品种樱桃番茄氨基酸组成及风味分析

为评价不同品种樱桃番茄的风味及营养价值,比较分析了8个品种樱桃番茄的可溶性固形物含量、总糖含量、有机酸含量、糖酸比、Vc含量、氨基酸含量和氨基酸组成。结果表明,红果樱桃番茄品种的部分风味指标(可溶性固形物、总糖、有机酸、Vc)、氨基酸组成及营养价值(总氨基酸、必需氨基酸含量及氨基酸模式谱)优于黄果品种,尤其是红果品种浙樱粉1号和浙樱红1号,其中,浙樱粉1号樱桃番茄可溶性固形物含量、总糖含量、有机酸含量、Vc含量、呈味类氨基酸(鲜味、甜味、芳香类)含量及氨基酸营养价值均处于较高水平。红果樱桃番茄品种之间的总糖含量、Vc含量,以及黄果樱桃番茄品种之间的有机酸含量、总氨基酸含量、必需氨基酸含量和甜味类氨基酸含量等指标均呈现出较低的变异系数。氨基酸营养价值分析表明,缬氨酸和亮氨酸是樱桃番茄的2个主要限制氨基酸。本研究结果为高品质樱桃番茄的品种选育提供了理论指导。     

Evidence for the involvement of arabinoxylan and xylanases in refrigerated dough syruping

The relationship between syruping in refrigerated doughs upon prolonged storage and different aspects of arabinoxylan (AX) hydrolysis was investigated using Triticum aestivum xylanase inhibitor (TAXI) and different xylanases in the dough formula. Dough characteristics were evaluated with strong emphasis on the AX population and its fate as a function of storage time. Selective reduction of part of the flour endogenous xylanase activity in dough by added TAXI reduced dough syruping after 12 and 20 days of storage by 50%, providing straightforward evidence for the involvement of xylanases and, thus, AX in the syruping phenomenon. Addition of xylanases with different inhibitor sensitivities [an inhibition-sensitive Bacillus subtilis xylanase (XBS(i)) as well as a noninhibited mutant (XBS(ni)) thereof] to dough confirmed the importance of xylanases in dough syruping, on one hand, and the power of wheat flour TAXI to constitute a significant barrier against xylanase-mediated dough syruping, on the other hand. Use of xylanases with different substrate selectivities [an Aspergillus aculeatusxylanase (XAA) versus XBS(ni)] showed degradation of water-extractable AX (WE-AX) and solubilized AX to low molecular weight molecules rather than the conversion of water-unextractable AX (WU-AX) to high molecular weight water extractable components to be the main factor influencing dough syruping.     

Effect of technological processing on the allergenicity of mangoes (Mangifera indica L.)

In parallel with the rising popularity of exotic fruits in Europe, allergy against mango is of increasing importance. Because mangoes are also consumed as processed products such as chutneys or beverages, the influences of different process conditions on their allergenicity were investigated. Mango purees and nectars were manufactured at small pilot-plant scale, and the allergenic potencies of the resulting intermediate and final products were determined by means of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), immunoblotting and inhibitive enzyme allergosorbent tests (EAST-inhibition), using a pool serum of 9 individuals with manifest mango allergy. The mango allergens were shown to be very stable during technological processing. Irrespective of enzymatic matrix decomposition, mechanical tissue disintegration and heating during peeling, mash treatment, and pasteurization, significant loss of allergenicity could not be observed in the extracts of mango purees and nectars derived thereof. These results were confirmed by analogous investigation of commercial mango drinks and nectars. Hence, conventional mango processing into pulp-containing products typical for this species obviously does not allow complete elimination of the allergenic potency.     

Release of soluble protein from peanut (Arachis hypogaea, Leguminosae) and its adsorption by activated charcoal

Peanut (Arachis hypogaea, Leguminosae) allergy is a major cause of food-induced anaphylaxis. The potential use of activated charcoal (AC) to adsorb and reduce the bioavailability of peanut protein allergens for use in the moderation of hypersensitivity reactions was investigated. The rate and extent of protein release from peanut and the adsorption of the solubilized protein by AC was determined under physiological pH values and confirmed in vivo using a porcine animal model system. Peanut proteins were adsorbed with equal efficiency at pH 2 and 7 and are completely removed from solution by an AC/protein ratio of approximately 80:1. This suggests that AC can bind protein under gastric (pH 2) or intestinal (pH 7) conditions. The rapid adsorption of soluble peanut allergens and the continuous binding of allergens released from peanut particulate material suggest the potential efficacy of using AC for gastric decontamination and possible elimination of a biphasic allergic reaction.     

Detecting potential IgE-reactive sites on food proteins using a sequence and structure database, SDAP-food

The high incidence of food allergies, including oral allergy syndrome, represent major considerations when introducing new crops and foods. A new structural database of allergenic proteins, SDAP-Food, http://fermi.utmb.edu/SDAP/, has been developed to aid in predicting the IgE-binding potential of novel food proteins and cross-reactivities among known allergens. The site is designed to facilitate the first steps of a decision tree approach to determine the allergenicity of a given protein, based on the sequence and structural similarity to known allergens and their IgE binding sites. Immunological tests can then be used to confirm the predictions. A hierarchical procedure for identifying potential allergens, using a physical property-based sequence similarity index, has been designed to identify regions that resemble known IgE binding sites. As an example, SDAP tools were used to find food allergen sequences similar to an IgE binding site of the Jun a 3 allergen from mountain cedar pollen. The SDAP sequence similarity search matched the Jun a 3 epitope to regions in several food allergens, including cherry (Pru av 2), apple (Mal d 2) and pepper (Cap a 1), which are, like Jun a 3, members of the plant pathogenesis-related (PR-5) protein family. Homology modeling, using our EXDIS/DIAMOD/FANTOM program suite, indicated a similar surface location and structure for the potential epitope region on all of these allergens. The quantitative approach presented here can be used as part of a screening process for potential allergenicity of recombinant food products.     

不同樱桃砧木对根际土壤微生物数量动态变化的影响

采用稀释平板测数法和最大或然数法研究樱桃年生长周期内不同樱桃砧木(大青叶、山樱、考特和马哈利)对根际与非根际土壤微生物数量动态变化的影响。结果表明,樱桃年生长周期内,4种樱桃砧木根际与非根际土壤微生物数量与其生长发育呈正相关,即土壤微生物数量从萌芽期开始增加,在开花期、坐果期或成熟期达到峰值,落叶期有所下降。不同樱桃砧木根际土壤微生物各生理类群数量差异显著,且均以细菌占绝对优势,放线菌次之,真菌最少。各樱桃砧木土壤微生物数量呈现根际效应。土壤根际微生物多样性指数的变化趋势与土壤根际微生物总数的变化趋势不一致。因此,选择合适的樱桃砧木,有利于土壤微生物数量的提高,从而为樱桃树生长创造良好的土壤微生态环境。     

Technological processes to decrease the allergenicity of peach juice and nectar

Among vegetable foods peach (Prunus persica) has been recognized as a significant cause of allergy. The protein, which is considered to be the major peach allergen, has been named Pru p 1. Because peaches are consumed both as fresh fruits and after processing to obtain peach juice, nectar, jam, syrupy peach, etc., research was carried out to identify a technological process for production of hypo- or nonallergenic peach-based products. SDS-PAGE and immunoblotting analysis of extracts prepared from four commercial peach nectars showed that the Pru p 1 was not removed, and neither was its allergenic activity decreased by technological treatments carried out for nectar production. Some treatments oriented toward a removal of or, at least, a decrease in the allergenic power were assumed and verified at laboratory scale. A variable considered was heat treatment at 121 degrees C for 10 and 30 min: this treatment was not able to decrease the allergenicity of the Pru p 1 protein. Furthermore, the protein band was still present even after 60-min reaction with two different acidic proteases. The two technological treatments that were found to decrease the major allergen of peach were chemical lye peeling of fruits and ultrafiltration of juice through membranes with suitable cutoff. On the basis of the results obtained from this research, a processing flow sheet was defined to obtain hypoallergenic or probably nonallergenic limpid juices and nectars. These products may represent, besides finished foods, intermediates to obtain various products after addition of further ingredients such as pectins, sugars, and fiber.     

Differential detection of shrimp and crab for food labeling using polymerase chain reaction

Shrimp and crab are well-known as allergenic ingredients. According to Japanese food allergy labeling regulations, shrimp species (including prawns, crayfishes, and lobsters) and crab species must be differentially declared when ≥10 ppm (total protein) of an allergenic ingredient is present. However, the commercial ELISA tests for the detection of crustacean proteins cannot differentiate between shrimp and crab. Therefore, two methods were developed to discriminate shrimp and crab: a shrimp-PCR method with postamplification digestion and a crab-PCR method that specifically amplifies a fragment of the 16S rRNA gene. The sensitivity and specificity of both PCR methods were verified by experiments using DNA extracted from 15 shrimp species, 13 crab species, krill, mysid, mantis shrimp, other food samples (cephalopod, shellfish, and fish), incurred foods, and commercial food products. Both PCR methods could detect 5 pg of DNA extracted from target species and 50 ng of genomic DNA extracted from incurred foods containing 10 ppm (μg/g) total protein of shrimp or crab. The two PCR methods were considered to be specific enough to separately detect species belonging to shrimp and crab. Although false-positive and false-negative results were obtained from some nontarget crustacean species, the proposed PCR methods, when used in conjunction with ELISA tests, would be a useful tool for confirmation of the validity of food allergy labeling and management of processed food safety for allergic patients.     

基于正交多项式回归试验的籽粒去皮关键参数建模分析

该文以甘蓝型油菜籽为试验材料，进行了小粒径农作物籽粒的碾搓法去皮的多因素多水平正交多项式回归试验。以未去皮率（P₁）和粉末率(P₂)为观测指标，分析了去皮装置的动齿螺旋角(β)、齿节距(t)、动齿盘转速(ω)和动定齿盘间隙(δ)等重要结构参数与观测指标的关系，得出了两者之间的回归方程数学模型，为小粒径籽粒去皮装置的优化设计打下了基础。     

Analysis of physicochemical factors related to the automatic pellicle removal in Korean chestnut (Castanea crenata).

Analyses were carried out for condensed tannin content, soluble sugar content, color, firmness, and peeling ratio of the pellicle of 14 varieties of Korean chestnut. The correlation between these physicochemical components and the peeling ratio was measured. The total soluble sugar content ranged from 4.20 to 11.83%. Condensed tannin contents in the inner and outer chestnut shells were 7.83-71.42% and 0.31-2.04%, respectively. In the outer shell of chestnut, CIE L* value was 26.98-33.34, CIE a value was 7.56-14.90, and CIE b value was 7.36-15.67. Firmness of chestnut was 4.41-9.20 kg. Peeling ratio of the pellicle by the peeling machine was significantly different with variety. The average peeling ratio was 63.79%, and that of the Okkwang variety was the highest at 85.29%. A negative correlation was found between tannin content of inner shell and peeling ratio (r = -0.57), but the correlation coefficients between other components and the peeling ratio were not significant.     

H_2S对低温胁迫下甜樱桃柱头和子房AsA-GSH循环的响应

为了探究H_2S对甜樱桃花器官低温伤害的缓解机理,以甜樱桃品种早大果为试材,分析了不同浓度H_2S供体NaHS对低温胁迫下甜樱桃柱头和子房AsA-GSH循环系统的影响。结果表明,喷施0.02、0.05、0.1 mmol·L~(-1)的NaHS均可降低低温胁迫下甜樱桃柱头和子房超氧阴离子(O_2~-)、过氧化氢(H_2O_2)、丙二醛(MDA)含量,显著提高还原型抗坏血酸(AsA)和还原型谷胱甘肽(GSH)含量(P0.05),降低氧化型抗坏血酸(DHA)和氧化型谷胱甘肽(GSSG)含量,使AsA/DHA和GSH/GSSG比值显著升高(P0.05),以0.05 mmol·L~(-1)NaHS效果最显著;0.02、0.05、0.1 mmol·L~(-1)的NaHS均显著提高低温胁迫下柱头和子房AsA-GSH循环中抗坏血酸过氧化物酶(APX)、脱氢抗坏血酸还原酶(DHAR)、单脱氢抗坏血酸还原酶(MDAR)、谷胱甘肽还原酶(GR)、谷胱甘肽过氧化物酶(GPX)和谷胱甘肽-S-转移酶(GST)的活性(P0.05),以0.05 mmol·L~(-1)NaHS提高上述酶活性的幅度最大。NaHS的浓度大于0.2 mmol·L~(-1)不再提高低温胁迫下AsA-GSH循环效率;低温胁迫下添加NaHS的同时添加H_2S清除剂HT可解除H_2S的效果。综上所述,喷施适量外源H_2S可有效降低低温胁迫下O_2~-、H_2O,和MDA积累,提高AsA-GSH循环效率,减轻低温对甜樱桃柱头和子房的氧化伤害。本研究结果为明确H_2S缓解甜樱桃花器官低温伤害作用机制以及生产上花期低温伤害预防提供了理论依据。     

叶面喷施磷酸二氢钾与葡萄糖对番茄光合速率和蔗糖代谢的影响

以辽园多丽和樱桃番茄红玉为试材,采用叶面喷施磷酸二氢钾、葡萄糖及其两者的混合液,研究叶面喷肥对两个品种番茄光合速率及蔗糖代谢的影响。结果表明:叶面喷肥可明显提高番茄叶片中叶绿素的含量及叶片的净光合速率。通过叶面喷肥处理,提高了2个品种番茄果实内果糖和葡萄糖的含量,提高了果实中酸性转化酶和中性转化酶的活力水平,蔗糖合成酶(SS)和蔗糖磷酸合成酶(SPS)活力也得到明显提高。以叶面喷施磷酸二氢钾及其与葡萄糖两者的混合液效果较好,单独喷施葡萄糖效果稍差。表明在叶面喷施葡萄糖、磷酸二氢钾和两者的混合液条件下,果实是通过提高4种酶的活力来提高库强度的。果实库强度增加的同时,相应地促进了同化产物的运转和干物质的积累。     

樱桃番茄苗期对淹水胁迫的响应及其耐涝性评价

为研究樱桃番茄苗期对淹水胁迫天数的响应规律及其耐涝性,选取千禧、立新佳禧、红妃6号、红钻石和台湾赞美5个热带地区常用樱桃番茄品种为试验材料,设置正常水分处理(CK)和淹水处理,对淹水胁迫下不同淹水天数(0、2、4、8和16 d)樱桃番茄苗期功能叶中超氧阴离子自由基(O2·-)含量、丙二醛(MDA)含量、抗氧化酶系统、渗透调节物质和根系活力等生理生化指标及株高、地上部干重、根系干重及根冠比等形态学指标进行了测定。结果表明,淹水前期,樱桃番茄叶片中O2·-和MDA含量多表现为先上升后下降的趋势,而在淹水后期千禧和立新佳禧品种则表现出迅速上升,并在淹水后16 d显著高于CK;叶片超氧化物歧化酶(SOD)活性在淹水后较CK多表现为下降趋势,仅红妃6号在淹水后16 d仍高于CK。过氧化物酶(POD)活性在淹水胁迫下较CK表现出先逐渐上升后下降的趋势,仅红钻石在淹水后期仍略高于CK,过氧化氢酶(CAT)活性仅红妃6号在淹水后2 d显著高于CK,其他品种CAT活性始终低于CK;叶片中可溶性糖和脯氨酸(Pro)的含量在淹水后显著增加。根系活力随着淹水处理时间的延长呈先上升后下降的趋势,且淹水后16 d千禧和立新佳禧品种根系活力较CK显著降低。淹水胁迫下,樱桃番茄株高、地上部干重、根系干重均低于CK;除千禧品种外,其他品种根冠比均高于CK,且红妃6号根冠比与CK间差异达到显著水平。利用主成分分析法对樱桃番茄品种耐涝性进行综合评价,得出各品种耐涝性大小排序:红妃6号>红钻石>台湾赞美>立新佳禧>千禧。本研究结果为热带地区樱桃番茄栽培品种选择及抗涝渍栽培机理研究提供了理论参考。     

Morphological characterization of sweet and sour cherry cultivars in a germplasm bank at Portugal

Nine sweet cherry and eight sour cherry varieties located in a germplasm bank at Fundão, Portugal, were studied from the viewpoint of characterization. Most of them were autochthonous cultivars that have a high risk of extinction since at the present they are markedly minor varieties. Morphological characteristics were evaluated in different organs: crown and trunk of the trees, leaves, flowers and fruits, over a three consecutive years period. Statistical analyses were carried out in order to detect similarities between cultivars as well as the existence of synonymies. Qualitative characteristics of the fruits were scored in order to carry out the multivariate analysis. A dendrogram of the evaluated characters shows the marked differentiation between sour and sweet cherries and suggests the existing synonymies. Conservation of the autochthonous cultivars in the future is highly recommended.     

Morphological characteristics of best Cornelian cherry (<Emphasis Type="Italic">Cornus mas</Emphasis> L.) genotypes selected in Serbia

On the territory of Serbia, the Cornelian cherry (Cornus mas L.) populations grow at different locations and on a variety of geological substrates and they represent a large and important genetic potential for use in breeding programs of this fruit species. Collection and study of Cornelian cherry genotypes, introduction of best selections in commercial production, and preservation of genetic variability are activities that could improve the existing fruit gene pool. In the Vojvodina Province, over 200 Cornelian cherry genotypes have been monitored at all stages of growth and development. Large variability has been observed in all morphological and chemical characteristics under study. This paper deals with 10 Cornelian cherry genotypes, which showed best morphological characteristics in a three-year study (2007–2009), which will be used for the development of standard Cornelian cherry varieties in Serbia.     

A Fruit Tree Stability Model for Static and Dynamic Loading

Static and dynamic tests were carried out on the trunk and main roots of cherry trees to obtain their important elastic and viscous properties. The horizontal and vertical displacement of the stem was measured at horizontal forces 80 cm above ground level. Force relaxation tests were carried out in the same way for 15 min. Main root samples were taken from a felled tree for bending, stressing and force relaxation tests. Accelerations of pre-stressed and released trunks were recorded for whole trees and for trunks when the limb was totally removed above 85 cm. From the static and dynamic test results a common model was composed of two Maxwell elements, a damping element and a spring, all coupled in parallel. During static loading, i.e. at force relaxation, the damping of the two Maxwell elements was active. During dynamic loading, when the trunk is swinging at its own frequency, only the single damping element acts together with the three parallel springs. The damping of the Maxwell elements is too high to influence the oscillations at the natural frequency.