Acrylamide in Processed Potato Products

Trace amounts of acrylamide are present in many foods cooked at high temperatures. Acrylamide in processed potato products is formed from reducing sugars and asparagine and is a product of the Maillard reaction; this reaction typically occurs during frying and baking of food products. Processed potato products, including fries and chips, are relatively high in acrylamide compared with other foods and contribute substantially to dietary acrylamide. Acrylamide content in potato products is strongly affected by processing conditions, potato variety, field management, environmental conditions during tuber growth, and tuber storage conditions. Numerous approaches have been described that could potentially reduce the acrylamide content of potato products, but many influence finished product sensory attributes and may be difficult to implement. Health concerns related to acrylamide in food center on its role as a potential carcinogen. Research using feeding studies with rodent models and epidemiological studies with humans are ongoing and are likely to provide future guidance for acceptable amounts of acrylamide in food.     

Effect of Cooking and Processing on CIPC Residue Concentrations in Potatoes and Processed Potato Products

Residue concentrations of the sprout suppressant chlorpropham (or CIPC) were determined in raw and cooked potatoes and processed potato products, 48 h after CIPC aerosol treatment and after 30 days of subsequent storage at 4 or 12 °C. In the raw (uncooked) tuber, 48 h after CIPC treatment, the CIPC residue in the peel was 4.7 mg kg^-1, while in the peeled tuber it was 0.1 mg kg^-1. Boiling resulted in a decrease in residue concentration in the peel, but no significant differences in the residue concentration of the peeled tuber were observed. Pressure cooking resulted in a significantly increased residue concentration in the peel, but no significant change in the peeled tuber, whereas microwave cooking also did not increase the residue concentration in the peel significantly compared with that in raw tubers. Also the trend towards increases in residue concentration in microwave-cooked peeled tubers was not significant. The CIPC residue concentration detected in peeled tubers was 0.4–0.7 mg kg^-1 after boiling, 0.4–1.5 mg kg^-1 after pressure cooking and 0.4–3.8 mg kg^-1 after microwave cooking. The highest values were always found for tubers stored for 30 days at 4 °C. Processed products such as crisps, French fries, dehydrated sliced potatoes and starch contained different concentrations of CIPC residue, which was also detected in the cooking water and frying oil. The highest residue concentrations detected were 0.7, 4.7, 1.3 and 0.2 mg kg^-1 in crisps, French fries, dehydrated sliced potatoes and starch, respectively. The highest CIPC residue concentration observed in raw potatoes was much lower than the maximum residue level of 10 mg kg^-1 prescribed by the European Union.     

影响马铃薯块茎品质性状的环境因子分析

马铃薯品质主要取决于块茎成分及其含量,包括淀粉、蛋白质、糖和维生素等。块茎内各成分的含量除受遗传基础和生理特性控制外,还主要因自然生态环境条件和人为栽培因素的不同而发生变化。本文主要介绍了影响马铃薯品质性状的光照、温度、水分、土壤特性等自然生态环境因素,以及种植密度、肥料、病虫害等人为栽培因素。通过对影响马铃薯块茎品质性状的生态条件和栽培因素的分析,进一步了解块茎品质与环境因子的相互关系和作用机理,为马铃薯引种工作提供一定的科学依据。     

马铃薯的养分需求

在综合了大量国内外关于马铃薯植株需肥研究资料的基础上,运用Excel进行统计分析生产1 000 kg马铃薯块茎的植株需肥量及影响其需肥的因素。结果表明,概率较高的1 000 kg马铃薯需N、P2O5、K2O的区间分别是3.0～4.0 kg,1.00～1.50 kg,4.0～6.0 kg。影响马铃薯养分需求量的因素有土壤有机质含量、土壤pH值、年份、产量等。明确单位产量的马铃薯需肥量及其影响因素,以期对我国的马铃薯测土配方施肥提供依据,对马铃薯因环境条件的差异而确定施肥量提供有益的信息。     

马铃薯不同品系贮藏期品质分析

马铃薯秋天入窖后,测定不同品系的还原糖含量、可溶性糖含量、淀粉含量,其结果为:还原糖含量入窖后到次年3月份逐渐升高,之后又快速下降,6-21还原糖含量最低,小白花还原糖含量最高;可溶性糖含量较稳定,只是不同品系表现趋势不同,6-21可溶性糖含量最低,1-38可溶性糖含量最高;淀粉含量也较稳定,6个品系总趋势为逐渐下降;1-38淀粉含量最高;大多数马铃薯品系的还原糖与可溶性糖呈正相关,可溶性糖与淀粉、还原糖与淀粉呈负相关。     

马铃薯高代系炸片色泽分析与加工品质评价

试验以241个高代系为材料,在块茎4℃贮藏40d后,对还原糖含量和炸片色泽进行了分析。结果表明,加工品种Atlantic薯片色泽指数(CCI)为4.33,在所测定的杂交后代中,04HE30-17等11个品系的CCI低于Atlantic。亲本组成分析表明,51-5、393160-4和395049.62为亲本的组合中,后代中出现油炸色泽较好品系的机率较高。     

Consumer Demand for Low-Acrylamide-Forming Potato Products: Evidence from Lab Auctions

A probable human carcinogen—acrylamide—was discovered about a decade ago to form naturally in potato products cooked at high temperatures. Using incentive compatible lab auctions and adult consumers from three distant U.S. locations, we test food labeling and information effects on willingness-to-pay (WTP) for conventional and genetically engineered potatoes, fries, and chips to reduce acrylamide levels. These new potato products are the first biotech products to have enhanced food safety for a popular food in the American and European diets. Relative to an environmental group’s perspective, scientific and industry information significantly increase WTP for biotech relative to conventional potato products. In addition, we find significant location-specific fixed effects of information treatments. Scientific and industry information can be used to nudge consumers towards improved decision making and healthy diets.     

Three-dimensional Stochastic Shape Modelling for Potato Tubers

Tuber shape is a genetically determined, important varietal characteristic that is also influenced by environmental factors. In this study, the overall dimensions of tubers of two potato cultivars (Van Gogh and Yukon Gold) were determined using a triaxial ellipsoid model that was found to encompass the main varietal differences. The more detailed surface features were captured using a spherical-harmonics series representation for the residual undulation. The method was then applied to four additional cultivars (Bellona, Lady Rosetta, Pito, and Sabina). Modelling the undulation of tuber surface in addition to the overall dimensions indicated that cultivars differed in the global shape and, in specific cases, also in the surface undulation of tubers. The new, improved method for modelling tuber shapes can thus capture and distinguish the overall three-dimensional shape and irregularities caused by growth conditions and other factors. It is envisaged to be useful for quantitative genetics approaches aiming to resolve the relative impact of different genes on tuber shape, as well as for various machine vision and other applications.     

几个加工型马铃薯品种主要品质形成的比较

以加工型马铃薯品种‘东农310’、‘东农314’、‘东农317’和‘大西洋’为材料,从块茎形成至淀粉积累期进行多次取样,比较几个品种的主要品质形成过程,探求块茎干物质、淀粉和粗蛋白含量的变化特性,以期为特定品种的优质丰产栽培提供参考。结果表明,随生育进程推进,几个加工型品种的干物质、淀粉和粗蛋白含量均极显著增加,整体表现为干物质含量呈单峰曲线、峰值出现在生育中期,淀粉含量在生育后期进入平台期,粗蛋白含量持续增加、在生育后期最高。‘东农310’的干物质、淀粉和粗蛋白含量均随生育进程推进而持续增加;‘东农314’的干物质、淀粉和粗蛋白含量呈单峰曲线,峰值出现在生育中期;‘东农317’的干物质和粗蛋白含量呈单峰曲线、峰值出现在生育中期,淀粉含量持续增加;对照品种‘大西洋’的干物质和淀粉含量呈单峰曲线、峰值出现在生育中期,粗蛋白含量持续增加。生育后期‘东农310’的干物质、淀粉含量均显著高于其他品种;‘东农310’、‘东农314’和‘大西洋’的粗蛋白含量差异不显著,‘东农317’的粗蛋白含量显著低于‘东农314’和‘大西洋’。     

马铃薯块茎休眠及休眠调控研究进展

系统介绍了马铃薯块茎休眠的总体特征以及休眠块茎在细胞生理学方面的研究进展.同时还论述激素对马铃薯块茎休眠的调节作用,并提出了一些打破休眠的方法。     

马铃薯块茎钾含量近红外模型的建立

为了快速测定马铃薯块茎中的钾含量这一品质性状,从而缩短育种时间,本研究使用InfraXact Lab型近红外分析仪测定马铃薯样品的近红外光谱值,并用常规化学分析方法测定马铃薯样品的含钾量,将这二者拟合建立定标模型。结果表明:钾含量定标方程的SECV值为0.072,而1-VR值为0.881,较接近1,钾含量的验证参数SEP(C)值为0.080,RSQ值为0.866,证明定标的预测能力较好,可以用其进行马铃薯育种材料钾含量的粗略测定。     

马铃薯块茎还原糖的测定方法比较

对传统的铜还原-碘量法和3,5-二硝基水杨酸比色法测定块茎烘干样中的还原糖进行了比较研究。结果表明,比色法的准确性和精密性均稍好于铜还原-碘量法,且操作简便、快速、环境及人为因素对其影响较小。     

Progress and Successes of the Specialty Crop Research Initiative on Acrylamide Reduction in Processed Potato Products

Acrylamide, a suspected human carcinogen, is a Maillard reaction product that forms when carbohydrate-rich foods are cooked at high temperatures. Processed potato products, including French fries and potato chips, make a substantial contribution to total dietary acrylamide. Health safety concerns raised by acrylamide in food increased financial risks to the potato industry and encouraged industry to take a proactive approach toward acrylamide mitigation. The USDA National Institutes of Food and Agriculture Specialty Crop Research Initiative (SCRI) on acrylamide reduction in potato was a cooperative endeavor in which industry partners worked at a systems level with university and government researchers to develop acrylamide mitigation strategies. Short-term goals focused on identifying advanced breeding clones and recently released varieties that have lower acrylamide-forming potential than standard potato varieties. Research was also directed at developing more efficient potato breeding methods, including marker-assisted breeding, genome wide selection, and improved phenotyping methods. Data from the National Fry Processing Trial (NFPT) and SCRI agronomic trial have shown that dramatic reductions in acrylamide are achievable through the use of new varieties that maintain low concentrations of tuber reducing sugars. Chipping potato trials coordinated by Potatoes USA and data from breeding populations suggest that maintaining low tuber reducing sugars through extended storage and lowering tuber asparagine content are options for decreasing acrylamide content in potato chips. To have an impact, new varieties must have exceptional agronomic performance and must produce finished products that meet requirements for consumer attributes including color, texture and taste. Data consistently show that this is more easily achievable in chipping potatoes than in fry processing potatoes.     

马铃薯杂交组合后代加工相关品质性状的评价

以马铃薯品种大西洋和东农303为母本的6个杂交组合的无性一代为试验材料,对其产量和加工相关品质性状进行评价。结果表明:综合表现最好的组合为大西洋×T1800,该组合产量高,平均单株产量可达604g;单薯重较高,平均单薯重可达80 g;高淀粉、低还原糖个体较多,后代中符合油炸加工类型的无性系比率最高。以东农303为母本的3个杂交组合后代比重偏低,但平均单株产量和平均单薯重均较高,可从这3个组合后代中筛选出高产鲜食的材料。     

Glycoalkaloid Concentration in Potato Tubers Related to Storage and Consumer Offering

Steroidal glycoalkaloids (SGA) are unwanted potato constituents for consumers because they are highly toxic and therefore have to be controlled in the food chain. Three experiments were carried out focusing on storage aspects and on exposure to artificial light at the point of sale. The experiments showed that an elevated temperature (10 °C) during long-term storage without sprouting inhibitors led to an increase in SGA contents (up to 518 mg SGA kg⁻¹ dry matter) in two of three investigated cultivars independent of the sprouting level. Cold storage (4 °C) slightly enhanced SGA contents in two cultivars. Sprout control resulted in a tendentious decrease in SGA contents in a set of another three cultivars. Growing location and wet and cool seasons had an influence too. Moderate exposure to light resulted in an increase in SGA in autumn, but in a decrease in spring time. Again, cultivars tested responded differently. The addressed factors have to be considered when developing strategies in minimising SGA level in table potatoes.     

大豆深加工产品的应用

以大豆为主料或辅料的深加工产品主要应用于食品、饮品、药品、饲料制品、纺织品、精细化工制品、建材制品及生物制剂等。1　大豆蛋白制品除以豆腐为中心的传统大豆制品外,以大豆蛋白为中心的新型大豆制品也开发出许多种。如:脱脂大豆粉,功能性浓缩大豆蛋白,组织大豆蛋白,分离大豆蛋白,多肽,蛋白发泡剂,大豆蛋白纺织纤维,海绵蛋白。高分子聚合材料。大豆蛋白制品不但蛋白质含量高,氨基酸组成好,含有丰富的钙、磷、铁,而且具有很多功能特性,如与水、脂肪的结合能力,乳化作用及泡沫形成能力,薄膜形成,凝胶作用,黏合作用等,因此被广泛应用…     

Effect of Packaging Material on Shelf Life and Quality of Ware Potato Tubers Stored at Ambient Tropical Temperatures

The effect of seven packaging materials (transparent perforated and non-perforated high-density polyethylene (HDPE) bags, black perforated and non-perforated low-density polyethylene (LDPE) bags, nylon gunny sacks, khaki bags and net bags) on post-harvest quality of tubers from three potato cultivars was evaluated. Data were collected on time and percentage of sprouting, weight loss rates and percentage tubers with greening and rotting. Packaging significantly reduced weight loss and rate of tuber greening but increased the rate of sprouting and decay incidences. Non-perforated PE bags were the most effective in reducing weight losses, recording losses of 0.7 to 0.9% after 32 days in storage while unpackaged tubers had weight losses of 11 to 12%. Tuber rotting was highest (60 to 66% of the tubers) in non-perforated PE bags. Greening was faster in non-packaged tubers recording 55 to 100% after 2 weeks in storage and showed high cultivar differences, but did not occur in black bags, whether perforated or non-perforated. Sprouting was complete by week 3 in all tubers packaged in non-perforated HDPE bags irrespective of cultivar. Although the non-perforated HDPE bag packaging prevented weight loss, its positive effect was counteracted by the high incidence of rotting and sprouting. Amongst the different materials evaluated, perforated low-density black PE bags were the best method for ware potato packaging due to low sprouting, reduced weight loss, low rate of tuber greening and reduced rate of tuber decay compared to other packaging materials. The study also indicated that the interaction between cultivars, packaging and storage period also affected shelf life of ware potatoes under ambient tropical conditions.     

Efficacy of Mineral Oil-Insecticide Mixtures for Protection of Potato Tubers Against PVY and PVM

The impact of a dozen mixtures of the most commonly applied aphicides: Mospilan 20 SP (acetamiprid), Pirimor 500 (pirimicarb) and Karate Zeon 050 CS (lambda-cyhalothrin), combined with the mineral oil Sunspray 850 EC, was researched in field conditions to assess their effectiveness in limiting potato tuber PVY, PVM and PLRV infection. In spite of the greatest reduction in the number of aphids occurring following application of Mospilan 20 SP, this treatment was not as effective in limiting PVY infection as, for example, applying Sunspray 850 EC mineral oil. Mineral oil, when used on its own or in a mixture with Pirimor 500 WG, was found to be the most effective measure for limiting PVY infection (the incidence of tubers infested with PVY was reduced by 64 % relative to control, i.e. no protection). A slightly weaker effect was observed in the case of a combination of the mineral oil with full doses of Karate Zeon 050 CS with a half of a dose of Mospilan 20 SP insecticide, however only for protection against PVY. A similar trend was observed for PVM even though a significant difference was only observed for Sunspray 850EC?+?Pirimor 500WG. In conclusion, the application of insecticide mixtures with mineral oil in protecting against PVY infection is not always as effective as the application of the oil itself only. Addition of the insecticide may sometimes improve the efficacy of protection, however, due to the extra costs involved, not always does it have to be economical.     

Glyphosate Carryover in Seed Potato: Effects on Mother Crop and Daughter Tubers

Field studies were conducted in 2008 and 2009 in Aberdeen, ID, Ontario, OR, and Paterson, WA to determine the effect of simulated glyphosate drift on ‘Ranger Russet’ potato during the application year and the crop growing the next year from the daughter tubers. Glyphosate was applied at 8.5, 54, 107, 215, and 423 g ae ha^?1 which corresponds to 1/00, 1/16, 1/8, ¼, and 1/2 of the lowest recommended single-application rate for glyphosate-resistant corn and sugar beet of 846 g ha^–1. Glyphosate was applied when potato plants were at 10 to 15 cm tall (Early), or at stolon hooking (H), tuber initiation (TI), or during mid-bulking (MB). In general, the MB applications caused less visual foliar injury to the mother crop than earlier applications at ID or OR, and H applications at WA. Mother crop injury increased as glyphosate rate increased regardless of location, application timing, and rating date. U.S. No.1 and total tuber yields were usually related to the injury level resulting from glyphosate application timings and rates. Although injury to the mother crop from glyphosate applied at MB usually was the lowest compared to injury from other application timings, when daughter tubers from that timing were planted the following year, emergence, plant vigor, and yield was most detrimentally impacted compared with that of daughter tubers from other timing treatments. MB daughter tuber emergence was less than 30 % of the nontreated control tuber emergence while emergence of daughter tubers from the other treatments was 60 to 95 %. As rate of glyphosate applied to the mother crop increased, daughter tuber emergence decreased. When MB daughter tubers did emerge, plants were chlorotic and stunted as if the plants had been directly sprayed with glyphosate. Regardless of whether the daughter tubers had defects or not, results the following year were the same. Implications are that if a mother seed crop encounters glyphosate during bulking, injury may not even be noticeable on the foliage or the tubers, however, emergence, vigor, and yield of the crop growing the following year from the daughter tubers could be greatly impacted.     

马铃薯不同贮藏阶段干物质变化规律研究初报

马铃薯贮藏期间(温度在1～4℃范围内)干物质含量变化呈"V"形趋势,马铃薯贮藏期间干物质含量变化与当地的气温变化一致,随着气温升高而升高,随着气温降低而降低,在1月份气温最低时马铃薯干物质含量也最低。