花生红衣中B型二聚体原花青素对丙烯酰胺的抑制效果

丙烯酰胺是一种公认的神经毒素和致癌物,近年来植物多酚抑制高淀粉食物热加工过程中丙烯酰胺形成的研究是食品安全领域研究工作的一个热点。为了研究低聚体原花青素对丙烯酰胺形成的抑制效果,以花生红衣原花青素(Peanut Skin Procyanidins,PSPc)混合物经过凝胶色谱分离后得到的第二个级分PSPc-2为原料,通过反相高效液相色谱-二极管阵列检测器(RP-HPLC-DAD)分析比较其在化学模拟体系和炸薯条食品体系中对丙烯酰胺的抑制效果,并通过反相高效液相色谱-质谱联用技术(RP-HPLC-ESI-MS/MS)对PSPc-2进行鉴定。结果表明:PSPc-2在化学模拟体系和炸薯条食品体系中对丙烯酰胺的抑制均呈非线性的浓度-抑制率关系,在化学模拟体系中,PSPc-2添加浓度为0.05 mg/m L时抑制率可达66.47±1.15%,在炸薯条食品体系中PSPc-2浸渍浓度为0.1 mg/m L时抑制率可达70.59±2.34%;PSPc-2由两种B型原花青素二聚体组成。     

花生红衣中黄烷醇抑制丙烯酰胺效果及其分离鉴定

目的研究花生红衣中提纯的原花青素(peanut skin procyanidins,PSPs-1)在化学模拟体系和食品体系中对丙烯酰胺产生的抑制效果,并对PSPs-1的组成成分进行鉴定。方法以天冬酰胺和葡萄糖反应产生丙烯酰胺作为化学模拟体系,以油炸薯条生成丙烯酰胺作为食品体系,通过HPLC分析PSPs-1对2种体系中丙烯酰胺的抑制效果,并采用反相高效液相色谱-电喷雾-质谱联用(RP-HPLC-ESI-MS/MS)技术对PSPs-1进行鉴定。结果在化学模拟体系中,PSPs-1具有明显的抑制丙烯酰胺生成的效果,并显示出非线性浓度效应,在添加量为0.1 mg/m L时达到最大抑制率,为(51.22?3.15)%;在食品体系中,PSPs-1的浓度及浸渍薯条时间皆对丙烯酰胺的产生有明显抑制效果,并显示一定的量效关系,PSPs-1浓度为0.1 mg/m L达到最大抑制率,为(51.03?2.97)%,且当浸渍时间为90 s时抑制效果最好(50.79±1.86)%。PSPs-1经RP-HPLC-ESI-MS/MS分析和与对照品比较,其可能是由含有儿茶素和表儿茶素的黄烷醇多酚组成。结论由儿茶素和表儿茶素组成的PSPs-1在2种体系中具有明显抑制丙烯酰胺产生的效果。     

基于体外消化模型研究板栗壳和囊衣原花青素类物质消化前后的组成差异

本文以板栗壳和囊衣为原料,采用基于超高效液相色谱-串联质谱（UPLC-MS/MS）技术的广泛靶向代谢组学,分析样品中原花青素物质经过模拟消化后的组成变化。结果显示,板栗壳和囊衣及其代谢物中共鉴定出33种原花青素类代谢物,差异代谢物分析显示,消化后板栗壳中表儿茶素、原花青素C2及原花青素A1等16种原花青素类化合物均呈显著（P<0.05）下调;板栗囊衣中没食子儿茶素-儿茶素-儿茶素、没食子儿茶素及没食子酸儿茶素没食子酸酯等17种原花青素类化合物均呈显著（P<0.05）下调。其中,下调最显著（P<0.05）的是没食子儿茶素-儿茶素-儿茶素,在体外胃肠消化后分别降低了98.23%（板栗壳）和97.86%（囊衣）。综上,板栗壳和囊衣中原花青素类物质在消化过程中稳定性较差,未来的研究中可采用设计靶向释放载体对其进行包埋等方式,以提高其生物利用率。     

凝胶色谱分离高梁外种皮中低聚体原花青素

建立高粱原花青素分离及其组成分析的方法。采用乙醇溶液提取高粱外种皮中原花青素,通过ADS-17大孔树脂初步纯化,得到高粱原花青素,进而用Toyopearl HW-40凝胶色谱对高粱原花青素分离,并用紫外光谱分析及高效液相色谱-二极管阵列检测法初步分析鉴定。结果表明：Toyopearl HW-40凝胶色谱分离得到A、B、C、D、E、F六个部分。经过紫外光谱分析初步鉴定出级分A、C、D、E、F均为原花青素,B为黄酮;经高效液相色谱-二极管阵列检测法分析可知,级分C和D分别为原花青素的二聚体B1和单体儿茶素,级分F为原花青素的低聚体。建立的高粱原花青素的分离分析方法效果良好。     

黑花生衣提取物抑制油炸马铃薯体系中丙烯酰胺形成的研究

本论文研究黑花生衣提取物对油炸马铃薯体系中丙烯酰胺形成的影响。采用黑花生衣中提取出的粗提物(BPSE)、原花青素(BPSP)、花色苷(BPSA)以及BPSP分级得到的M1、M2和M3三种不同平均聚合度的原花青素,分别将6种物质添加到马铃薯粉中,油炸后,用高效液相色谱检测丙烯酰胺含量;选择最佳抑制率最大的物质进行动力学试验。结果表明,BPSE、BPSP、BPSA、M1、M2和M3对丙烯酰胺的最佳抑制浓度分别为0.1μg/mL、1μg/mL、0.1μg/mL、1μg/mL、0.01μg/mL和0.1μg/mL,最佳抑制率分别为39.78%、60.63%、25.18%、53.35%、49.02%和43.75%,原花青素能很好地抑制丙烯酰胺形成。通过比较BPSP试验组、空白对照组和橙皮苷阳性对照组对油炸马铃薯体系中丙烯酰胺的形成动力学过程,得出丙烯酰胺在200 s时,生成量最高,BPSP可以有效抑制丙烯酰胺的形成过程。     

猕猴桃果实中酚类物质的分离鉴定及抗氧化活性

采用高速逆流色谱与制备型高效液相色谱联用技术对猕猴桃果实中酚类化合物进行分离,共获得8 种化合物。利用波谱方法鉴定出7 种化合物,分别为：新绿原酸（化合物1）、咖啡酸-3-O-葡萄糖苷（化合物2）、2-O-咖啡酰基苏糖酸（化合物3）、表儿茶素（化合物5）、原花青素C1（化合物6）、Malaxinic acid（化合物7）、槲皮苷（化合物8）。化合物4经初步推测为B-型原花青素二聚体。化合物2、5、6、7对1,1-二苯基-2-三硝基苯肼和2,2’-联氮-二-(3-乙基-苯并噻唑-6-磺酸)阳离子自由基都有清除效果,清除能力排序为：原花青素C1＞表儿茶素＞咖啡酸-3-O-葡萄糖苷＞Malaxinic acid。     

红莲外皮原花青素各级分的分析鉴定

以分级分离得到的4 种红莲外皮原花青素级分（F1、F2、F3、F4）为原料,分别进行平均聚合度的测定,通过红外光谱、反相-高效液相色谱以及反相高效液相色谱和电喷雾质谱联用分析,以揭示不同级分的组成和化学结构特征。结果表明 F1、F2、F3、F4的平均聚合度分别为2.12、7.27、7.85、8.16。F1、F2、F3和F4的红外光谱图均表现出明显的原花青素特征骨架振动,并推测出红莲外皮原花青素的主要结构单元是原花青定。F1的反相高效液相色谱和电喷雾质谱联用分析检测出3 种单体、4 种二聚体和2 种四聚体,其中3 种单体分别为棓儿茶素、儿茶素、表儿茶素,4 种二聚体和2 种四聚体都是由儿茶素或表儿茶素聚合而成。F2、F3和F4的反相高效液相色谱分析均检测出儿茶素单体和表儿茶素单体。通过与F1的高效液相色谱图对比,推断出F2、F3和F4均含有3 种二聚体,并且其中1 种二聚体含量较多。同时F2、F3、F4中还存在一种含量较多的未知组分。     

红莲外皮原花青素的纯化与分析

原花青素作为多酚的一大类广泛存在于天然植物中。红莲外皮原花青素粗提取物采用大孔树脂AB-8和聚酰胺柱进行两次纯化。纯化物通过红外光谱（infrared spectrum,IR）和电子喷雾离子化质谱（electrosprayionization-mass spectroscopy,ESI-MS）对成分进行分析,并通过反相液相色谱-质谱（reverse phase high-performanceliquid chromatography- mass spectroscopy,RP-HPLC-MS/MS）联用对组分进行分离鉴定。结果表明：纯化物中有9 种原花青素单体和低聚体,其中包括儿茶素和表儿茶素（m/z 289）、棓儿茶素（m/z 305）,4 种原花青定二聚体的同分异构体（m/z 577）和2 种原花青定四聚体的同分异构体（m/z 1 153）。     

薄层色谱法分离葡萄籽中的低聚原花青素

通过对不同溶剂展开体系的选取,确定低聚原花青素分离的薄层色谱展开体系为v(甲苯)∶v(丙酮)∶v(乙酸)=3∶3∶1.从原花青素中分离制备得到儿茶素的单体、二聚体、三聚体,运用高效液相色谱对其进行了分析验证.     

原花青素对Glu-Asn体系中丙烯酰胺的抑制作用研究

本文选取荔枝原花青素(LPPC)和莲房原花青素(LSPC)进行丙烯酰胺抑制作用的研究。实验发现两种原花青素的浓度-抑制率关系均呈非线性关系,当LPPC和LSPC的添加量分别0.5 mg·m L-1和0.1 mg·m L-1时,丙烯酰胺的抑制率达到最大,分别为53.01%±5.62%和76.60%±3.20%;同时也探讨了体系中抗氧化性、色度和类黑精含量与抑制率的关系。结果表明体系抗氧化性越大,丙烯酰胺的抑制率就越高;白度越大,丙烯酰胺抑制率就越大;类黑精含量越大,丙烯酰胺的抑制率反而越低。总体来说,原花青素能显著地抑制丙烯酰胺的形成。     

Effective quality control of incoming potatoes as an acrylamide mitigation strategy for the French fries industry

The correlation between sugar levels in raw material (potatoes), brown colouring and formation of acrylamide in French fries was investigated. The objective was to identify incoming potatoes (raw material) with a high potential for acrylamide formation. Ten different potato varieties commonly used in the Western European French fries industry were stored at 8°C and samples were taken throughout the storage time. The current quality control used in the French fries industry for incoming potatoes is poorly correlated with acrylamide in the final product (r = 0.74). Changing the quality control parameter from colour to reducing sugars in raw material did not improve the correlation (r = 0.72). The best correlation was obtained with the Agtron colour measurement after blanching and a two-stage frying (r = ?0.88). It was concluded that alternative entrance control measurements could provide better mitigation of the acrylamide issue in French fries from the start of production. These alternatives, however, are less cost-effective and more difficult to implement.     

Influence of deep-frying using various commercial oils on acrylamide formation in French fries

This study investigated the effect of different types of commercial oils (rice bran oil, shortening oil, high-oleic rapeseed oil, low-erucic acid rapeseed oil, blend oil A and blend oil B) and frying cycles on acrylamide formation during the preparation of French fries by deep-frying. Frying was carried out in intermittent mode (two batches each for 12 min without any time lag) and repeated for 600 frying cycles. Results indicated that the French fries that were fried in oils having lower heat transfer coefficients contained lower acrylamide concentrations (913 µg kg^–1), whereas those fried with oils having higher heat transfer coefficients contained higher acrylamide concentrations (1219 µg kg^–1). Unlike the peroxide value, acrylamide levels in French fries did not change significantly with an increase in the number of frying cycles when tested for 600 frying cycles for every type of oil. This study clearly indicates that the contribution of frying oils to the formation of acrylamide should not be neglected due to their different heat transfer coefficients. On the other hand, continuous use of frying oil does not lead to a higher acrylamide concentration in French fries.     

The effects of low‐temperature potato storage and washing and soaking pre‐treatments on the acrylamide content of French fries

BACKGROUND: Since the discovery in 2002 of acrylamide in a wide range of foods, there has been much work done to explore mechanisms of formation and to reduce acrylamide in commercial products. This study aimed to investigate simple measures which could be used to reduce acrylamide formation in home‐cooked French fries, using potatoes from three cultivars stored under controlled conditions and sampled at three time points. RESULTS: The reducing sugar content for all three cultivars increased during storage, which led to increased acrylamide levels in the French fries. Washing and soaking (30 min or 2 h) raw French fries before cooking led to reductions in acrylamide of up to 23, 38 and 48% respectively. Pre‐treated fries were lighter in colour after cooking than the corresponding controls. CONCLUSION: Pre‐treatments such as soaking or washing raw French fries in water reduce acrylamide and colour formation in the final product when cooking is stopped at a texture‐determined endpoint. Copyright © 2008 Society of Chemical Industry     

Acrylamide in Romanian food using HPLC-UV and a health risk assessment

The aim of this study was to investigate the level of acrylamide from coffee, potato chips and French fries in Romanian food. According to the European Food Safety Authority, coffee beans, potato chips and French fries have the highest levels of acrylamide. For this survey, 50 samples of coffee beans, 50 samples of potato chips and 25 samples of French fries were purchased from different producers from the Romanian market. Acrylamide levels have been quantified using high-performance liquid chromatography with a diode array detector (HPLC-DAD) method, using water as mobile phase. Health risk assessment was achieved by computing the average daily intake, hazard quotient, cumulative risk, carcinogenic risk and cancer risk. For coffee, potato chips and French fries, acrylamide was not shown to pose a health risk in Romanian food.     

Development and experimental validation of a frying model to estimate acrylamide levels in French fries

ABSTRACT:  In this study, a numerical model was developed to simulate frying of potato strips and estimate acrylamide levels in French fries. Heat and mass transfer parameters determined during frying of potato strips and the formation and degradation kinetic parameters of acrylamide obtained with a sugar–asparagine model system were incorporated within the model. The effect of reducing sugar content (0.3 to 2.15 g/100 g dry matter), strip thickness (8.5 × 8.5 mm and 10 × 10 mm), and frying time (3, 4, 5, and 6 min) and temperature (150, 170, and 190 °C) on resultant acrylamide level in French fries was investigated both numerically and experimentally. The model appeared to closely estimate the acrylamide contents, and thereby may potentially save considerable time, money, and effort during the stages of process design and optimization.     

A survey of acrylamide precursors in Irish ware potatoes and acrylamide levels in French fries

Reducing sugars (glucose and fructose) and asparagine levels in three varieties of Irish ware potatoes (Rooster, Record and Oilean) on sale in a local supermarket were monitored over an 11-month period. Samples were processed into French fries using conditions similar to those used for home preparation of fries and acrylamide levels in a selection of samples were measured. A wide range of total reducing sugar levels (fructose+glucose) were observed over the course of the study with values ranging from 152-12,286, 301-8812 and 279-7881 μg/g FW for the Rooster, Record and Oilean varieties, respectively. This resulted in high levels of acrylamide in some samples (up to 2970 μg/kg). In comparison to reducing sugars, asparagine contents were relatively constant for the three varieties and no particular trend in asparagine levels was noted. Both fructose and glucose contents of the tubers were positively correlated with acrylamide content (r=0.809, 0.776, respectively, P<0.001). A negative relationship between Hunter L values and acrylamide content of the French fries was observed (r=−0.712, P<0.001) indicating that L values could serve as a convenient and reliable indicator of acrylamide levels in French fries.     

ANALYSIS AND FORMATION OF ACRYLAMIDE IN FRENCH FRIES AND CHICKEN LEGS DURING FRYING

The analysis and formation of acrylamide in French fries and chicken legs during frying were studied. Results showed that the most appropriate extraction solvent was ethyl acetate, with C‐18 cartridge for purification and 5‐mL deionized water as elution solvent. Dibromination of acrylamide followed by dehydrobromination to 2‐bromopropionamide in the presence of triethylamine was necessary for subsequent analysis by gas chromatography–mass spectrometry. The most appropriate temperature programming condition was as follows: 70C in the beginning, raised to 150C at a rate of 10C/min, maintained for 1 min and to 240C at a rate of 30C/min, maintained for 5 min. Detection was carried out using selected‐ion monitoring mode, and N,N‐dimethylacrylamide was used as internal standard for quantification. French fries and the outer flour portion of chicken legs fried at 180C generated a higher level of acrylamide than at 160C. Compared to soybean oil and palm oil, a lower amount of acrylamide was produced in French fries and the outer flour portion of chicken legs fried in lard. However, no acrylamide was detected in the inner meat portion of fried chicken legs.     

The effect of asparaginase on acrylamide formation in French fries

Acrylamide formation in French fries was investigated in relation to blanching and asparaginase soaking treatments before final frying. Par-fried potatoes of Bintje variety were prepared by cutting strips (0.8 × 0.8 × 5 cm) which were blanched at 75 °C for 10 min. Unblanched strips were used as the control. Control or blanched strips were then dried at 85 °C for 10 min and immediately partially fried at 175 °C for 1 min. Finally, frozen par-fried potatoes were fried at 175 °C for 3 min to obtain French fries. Pre-drying of raw or blanched potato strips did not generate acrylamide formation as expected. Partial frying of pre-dried control potato strips generated 370 μg/kg of acrylamide and the final frying determined French fries with 2075 μg/kg of acrylamide. When control potato strips were treated with a 10000 ASNU/l asparaginase solution at 40 °C for 20 min, the acrylamide formation in French fries was reduced by 30%. When blanched potato strips were treated in the same way, the produced French fries have 60% less acrylamide content than blanched strips without the enzyme treatment. Soaking of blanched potato strips (75 °C, 10 min) in an 10000 ASNU/l asparaginase solution at 40 °C for 20 min is an effective way to reduce acrylamide formation after frying by reducing the amount of one of its important precursors such as asparagine.