济南市早餐油条中铝含量检测结果分析

目的了解济南市早餐油条中铝的含量。方法按照国家标准GB/T5009.182-2003《食品中铝的检测》方法检测。结果46份样品中只有3份合格,合格率仅为6.5%。结论济南市早餐油条市场上存在着较为严重的明矾滥用现象。     

Effect of frying oil quality and TBHQ on the shelf-life of potato crisps

Three different systems were used for the evaluation of the effect of frying oil quality and tertiarybutyl hydroquinone (TBHQ) on the shelf-life of fried potato crisps. Batches of potato slices were fried for 4 min at 30 min intervals over a period of 5 h day^?1 for eight consecutive days in refined, bleached and deodorised palm olein (RBD olein) without antioxidant (system 1); RBD containing 200 μg g^?1 TBHQ at the start of the experiment (system 2) and RBD olein which had TBHQ topped up to a level of 200 μg g^?1 at the start of each frying day (system 3). Sensory evaluation of crisps showed that there is an initial rapid decrease in shelf-life with increase in fry number in all systems. There was only a comparatively smaller effect on shelf-life with increase in fry number in later fryings. When the shelf-life of crisps was related to the quality of oil in the frying medium, it was found that the shelf-life of the product is only slightly affected when the oil had deteriorated beyond the acceptable limit of quality of frying oil, where the acceptable limit was taken as 27-30% polar components and 1–2 mg potassium hydroxide g^?1 oil. TBHQ does have a protective carry-through effect. The protective effect is more pronounced when TBHQ is topped up to a level of 200 μg g^?1 at the beginning of each frying day.     

液相色谱联用电化学还原装置检测油炸食品中叔丁基对苯二酚

目的:采用液相色谱联用电化学还原装置检测油炸食品中叔丁基对苯二酚。方法:样品经石油醚提取得到油脂,再加入乙腈萃取,离心过滤,上机测定。结果:在0.50 50.00mg/L浓度范围内线性良好,相关系数r=0.9971,方法最低检测限为0.05mg/L,RSD=1.78%,加标回收率84.20 91.21%。结论:该方法前处理简便快捷,采用电化学方式还原了油炸食品在生产及储存过程中被氧化的TBHQ,精密度、准确度好,检测结果准确可靠。     

Co-contamination of aflatoxin B1 and fumonisin B1 in food and human dietary exposure in three areas of China

Aflatoxins and fumonisins are ubiquitous foodborne toxicants and the co-occurrence of these mycotoxins in human foods represents a significant public health concern, which has been strongly associated with human aflatoxicosis, neural tube defects, as well as many types of primary cancers. In this study the co-contamination of aflatoxin B₁ (AFB₁) and fumonisin B₁ (FB₁) in food and human dietary exposure was investigated in residents of three different areas of China. A total of 209 food samples were measured for AFB₁ and FB₁. The median AFB₁ levels were 13.5, 2.3 and 1.3?µg?kg^?1 and the median FB₁ levels were 2.6, 0.4 and 0.3?mg?kg^?1 in corn samples collected from Huaian (a high-risk area for oesophageal cancer), Fusui (a high-risk area for liver cancer) and Huantai (a low-risk area for both oesophageal and liver cancers), respectively. The median level of AFB₁ in plant oil of Fusui was the highest (52.3?µg?kg^?1) among all food samples analysed. Co-contamination of these two mycotoxins was found in corn, rice and wheat flour. Based on measured food consumption data, the averaged daily dietary intake of AFB₁ was 0.397?µg (range?=?0.269–1.218?µg) in residents of Huantai, 1.723?µg (0.224–49.772?µg) in Huaian, and 2.685?µg (1.006–14.534?µg) in Fusui. The averaged FB₁ daily dietary intake was 92.4?µg (range?=?55.0–362.1?µg) for residents of Huantai, 460.0?µg (83.2–2894.5?µg) in Huaian, and 138.6?µg (30.0–10,541.6?µg) in Fusui. These data suggest that the co-exposure to AFB₁ and FB₁ in residents of rural China may contribute to the aetiology of human chronic diseases in high-risk areas.     

乳酸发酵对油炸藕片质量的影响

本实验研究了乳酸发酵对油炸藕片质量的影响。结果表明:乳酸发酵可有效降低鲜藕中还原糖含量;对于还原糖含量较高者(>0.4%),发酵6h可以使炸片获得最佳色泽;对于还原糖含量较低者(<0.4%),乳酸发酵对色泽改善意义不大。乳酸发酵可以使油炸藕片综合质量提高。     

Quality Mapping and Positioning of Sev—A Deep Fat Fried Snack

“Sev,” savory prepared from chickpea flour is a popular snack item for its appealing flavor and texture. Mapping and positioning of market samples consisting different varieties like Small (S1, S2, S3), Medium (M1, M2, M3), and Big (B1, B2, B3, B4) were carried out using principal component analysis. Samples were subjected to sensory profiling resulting in small variety samples were crisper compared to other varieties. Texture measurement indicated breaking strength was higher in big variety samples. Color analysis showed significant difference in L*, a*, and b* values. Principal component analysis results indicated that S1 and S2 were associated with crispness, uniform texture, and typical fried oil aroma. Commercially available sev samples were significantly different in their quality parameters, which was indicated by the study. Study showed that small variety (S3) had the highest overall quality among all the samples, which also had high sensory scores for crispness.     

Effect of initial aflatoxin concentration,heating time and roasting temperature on aflatoxin reduction in contaminated peanuts and process optimisation using response surface modelling

Response surface methodology was applied to optimise the aflatoxin reduction in both naturally and artificially contaminated samples using dry oven. The effect of initial aflatoxin concentration (0–400 ng g^?1), heating time (30–120 min) and temperature (90–150 °C) was evaluated. The maximum reduction of AFB1 (78.4%) and AFB2 (57.3%) of artificially contaminated samples with initial aflatoxin concentration of 237 and 68 ng g^?1, and those of AFG1 (73.9%) and AFG2 (75.2%) with initial aflatoxin concentration of 215 and 75 ng g^?1 was obtained at 150 °C. The maximum reduction of AFB1 (80.2%) and AFB2 (69.7%) of naturally contaminated samples with initial aflatoxin concentration of 174 and 25 ng g^?1 was obtained at 150 °C and 130 °C, respectively.     

Flavor stability of high-oleic peanuts stored at low humidity

Shelf-life studies were conducted on roasted high-oleic peanuts (HOP; F1250, BC93Q10) and a reference peanut with normal oleic acid content (NOP, Florunner). HOP contained at least 80% oleic acid and 3% linoleic acid, whereas normal-oleic peanuts contained 53% oleic and 27% linoleic acids. Peanuts were dry-roasted to a medium roast (Hunter lab L=50) and stored at 40°C at 18% relative humidity. Samples were removed from storage at different intervals (0, 2, 4, 7, and 10 wk) for sensory evaluation and chemical oxidation measurements. Sensory attributes rated included roasted peanutty flavor, sweetness, crunchiness, and oxidized flavors (cardboardy and painty). The two HOP lines were not significantly different from each other in flavor quality or stability during storage but had better flavor quality and stability than NOP. The latter oxidized faster and developed painty off-flavors to a greater extent than did the HOP lines. Chemical oxidation measurements confirmed higher levels of oxidation in NOP than in the HOP lines. Peroxide values at 10-wk storage were 47 meq/kg oil for NOP and <3 meq/kg oil for the HOP lines. Both HOP lines had greater shelf lives than NOP.     

计算机视觉技术在花生破损检测中的应用

运用计算机视觉技术对花生的破损进行了研究。首先获取花生图像,利用图像去噪、图像分割、图像增强等多种基本图像处理的方法对花生破损图像进行了处理。其次,对花生图像进行了特征分析、颜色切割。然后根据拍摄的花生图像的像素之比得出破损率。本研究方法不但节省了时间和人力,且提高了精度。     

Maturity and Storage Affect Freeze Damage in Peanuts

Maturity and length of storage times were studied as factors influencing chemical properties of peanuts harvested at six different dates and artificially freeze damaged for 10 hr at ?4°C. Conductivity of water extracts from freeze damaged peanuts generally decreased with maturity as did the amount of potassium found in the leachatcs. Two freeze-damage products, acetaldehyde and ethanol, decreased with maturity, indicating that maturity affected the extent of freeze damage. Acetaldehyde and ethanol concentrations also decreased during storage of freeze-damaged peanuts.