Persistence of chlorpropham (CIPC) in the concrete flooring of potato stores

The loss of the sprout suppressant, chlorpropham (CIPC), to the fabric of potato stores is currently of concern due to the risk of potential cross contamination of other crops subsequently housed in these stores. HPLC UV/VIS and GCMS methods were successfully employed to detect CIPC in the concrete flooring of research and commercial potato stores with histories of between 1 and 26 years of use. The concentrations in identical research stores, with different numbers of applications, were in the range 0.58–5.7 and 3.4–112 μg g−1, suggesting the magnitude of contamination was influenced by the number of applications. Commercial store A, with a history of 18 seasons of applications (estimate of total CIPC applied 2040 kg), had concentrations varying between 6 and 48 μg g−1 in the top three centimetres, with more than 92% within the top centimetre. In contrast, commercial store B, with a history of less than five seasons of applications (estimate of total CIPC applied 319 kg), had concentrations varying between 0.58 and 304 μg g−1 in the top four centimetres, with less than 47% within the top centimetre. The difference in depth distributions between A and B may be due to the structural integrity of the concrete, which was much poorer in B. CIPC was persistent in all stores irrespective of the total quantities of CIPC applied and date of the final application

Determination of Chlorpropham (CIPC) residues, in the concrete flooring of potato stores, using quantitative (HPLC UV/VIS) and qualitative (GCMS) methods

Isopropyl-N-(3-chlorophenyl) carbamate (CIPC, common name Chlorpropham) is commonly used for post-harvest sprout inhibition in stored potatoes. It is applied as a thermal fog which results in loss to the fabric of the store and the atmosphere. Recently, there have been concerns in the United Kingdom because of cross contamination of other crop commodities that were stored in buildings with a history of CIPC usage. This cross contamination may have occurred because of retained residues in the fabric of the stores. The retention of CIPC in concrete is poorly understood; therefore the requirement for a robust analytical method for the detection and quantification of CIPC in concrete is a critical first step in tackling this problem. A method using High-Performance Liquid Chromatography with ultraviolet detection (HPLC UV/VIS) was validated. CIPC recoveries at three concentration levels (0.4, 4.0 and 40.0 µg g-1) were in the range of 90.7-97.0 % with relative standard deviations between 2.14-3.01 %. The limits of detection and quantification were 0.03 and 0.1 µg g-1 , respectively. This study confirmed that CIPC was persistent in concrete to a depth of 4 cm, with > 90 % within the top 1 cm of the flooring

The risk of chlorpropham cross-contamination of grain in potato stores

The contamination of food with pesticide residues is of significant concern to consumers and legislation has been implemented worldwide to ensure compliance with Maximum Residue Levels of chemicals in food. The occurrence of the potato sprout inhibitor, isopropyl N-(3-chlorophenyl) carbamate (chlorpropham or CIPC) residues on cereals, such as wheat, is of concern as this chemical is not authorised for use on cereals, and therefore the route of unintentional contamination warrants further investigation. This study reports on the risk of CIPC cross-contamination of grain that was stored in a commercial potato store and provides a method for low level quantification of CIPC in cereals. A High Performance Liquid Chromatography (HPLC UV/VIS) method for quantifying residues of CIPC in grains was successfully validated and the presence of CIPC was confirmed by Gas Chromatography Mass Spectrometry (GCMS). The magnitude of contamination in the grain was influenced by: (I) direct contact with the flooring of the store; (II) the headspace directly above the concrete surface and within the store itself and (III) contaminated dust/CIPC particles in the store atmosphere. Cross contamination is feasible irrespective of the CIPC concentrations in the concrete flooring and even with storage of grain at an elevated height above the concrete, suggesting that the route of cross contamination is a complex process involving physical and chemical (volatilization) factors. The results are significant for recommendations involving the storage of grain in buildings with a history of CIPC use and for remedial strategies for decontamination of these buildings

Acrylamide in potato crisps prepared from 20 UK-grown varieties: effects of variety and tuber storage time

Twenty varieties of field-grown potato were stored for 2 months and 6 months at 8 °C. Mean acrylamide contents in crisps prepared from all varieties at both storage times ranged from 131 μg per kg in Verdi to 5360 μg per kg in Pentland Dell. In contrast to previous studies, the longer storage period did not affect acrylamide formation significantly for most varieties, the exceptions being Innovator, where acrylamide formation increased, and Saturna, where it decreased. Four of the five varieties designated as suitable for crisping produced crisps with acrylamide levels below the European Commission indicative value of 1000 μg per kg (Saturna, Lady Rosetta, Lady Claire, and Verdi); the exception was Hermes. Two varieties more often used for French fries, Markies and Fontane, also produced crisps with less than 1000 μg per kg acrylamide. Correlations between acrylamide, its precursors and crisp colour are described, and the implications of the results for production of potato crisps are discussed

Acrylamide-forming potential of potatoes grown at different locations, and the ratio of free asparagine to reducing sugars at which free asparagine becomes a limiting factor for acrylamide formation

Acrylamide is produced from free asparagine and reducing sugars during high-temperature cooking and food processing, and potato products are major contributors to dietary acrylamide intake. The present study analysed twenty varieties of potatoes grown at two sites (Doncaster and Woburn) in the United Kingdom to assess the effect of location of cultivation on acrylamide-forming potential. Analysis of variance revealed a full site by variety nested within type (French fry, boiling and crisping) by storage interaction for acrylamide (p < 0.003, F-test), reducing sugars and total sugars (p < 0.001, F-test). There was much greater free asparagine in potatoes grown at the Doncaster site compared with the Woburn site. Modelling of the relationship between the ratio of free asparagine to reducing sugars and the levels of acrylamide identified a value of 2.257 ± 0.149 as the tipping point in the ratio below which free asparagine concentration could affect acrylamide formation

Research Review: Senescent Sweetening of Potatoes

Aim: To review currently available information in order to identify the research required to improve understanding of the factors controlling the rate of senescence, and amelioration of the condition during storage. Industry Challenge Prolonged storage of potatoes leads to a form of sugar accumulation termed ‘senescent sweetening’ that is generally associated with a loss of cell membrane integrity within the tuber over time. Although some information is available regarding the nature and causes of senescent sweetening, a greater understanding about the factors controlling the rate of senescence and how to ameliorate the condition during storage would be extremely beneficial to the GB potato industry. Collaboration Natural Resources Institute (NRI) and Sutton Bridge Crop Storage Research (SBCSR) Approach The main topics of this review to be covered are: - The nature of tuber senescence - Factors affecting the rate of tuber senescence - Indicators of tuber maturity - Potential early indicators of the onset of senescence and associated sweetenin

Relationship between alkylpyrazine and acrylamide formation in potato chips

Levels of acrylamide and fourteen alkylpyrazines were measured in chips made from twenty cultivars of potato, which had been stored for two and six months. While a significant correlation existed between acrylamide and total pyrazines (r 2 = 0.609; p = 0.001) for the studied samples, this correlation was not as great as those that existed between the 14 pyrazines themselves (r 2 = 0.607–0.965). Levels of pyrazines varied significantly with cultivar (p = 0.0001), while for the cultivars Innovator and Lady Rosetta most pyrazines increased on storage. The ratio between acrylamide and total pyrazines was examined. Low-acrylamide chips that are relatively high in alkylpyrazines (Verdi, Lady Claire, Lady Rosetta and Fontane) may be of interest to manufacturers