The effect of chemical treatment on reduction of aflatoxins and ochratoxin A in black and white pepper during washing

The effect of 18 different chemicals, which included acidic compounds (sulfuric acid, chloridric acid, phosphoric acid, benzoic acid, citric acid, acetic acid), alkaline compounds (ammonia, sodium bicarbonate, sodium hydroxide, potassium hydroxide, calcium hydroxide), salts (acetate ammonium, sodium bisulfite, sodium hydrosulfite, sodium chloride, sodium sulfate) and oxidising agents (hydrogen peroxide, sodium hypochlorite), on the reduction of aflatoxins B₁, B₂, G₁ and G₂ and ochratoxin A (OTA) was investigated in black and white pepper. OTA and aflatoxins were determined using HPLC after immunoaffinity column clean-up. Almost all of the applied chemicals showed a significant degree of reduction on mycotoxins (p?<?0.05). The lowest and highest reduction of aflatoxin B₁, which is the most dangerous aflatoxin, was 20.5%?±?2.7% using benzoic acid and 54.5%?±?2.7% using sodium hydroxide. There was no significant difference between black and white peppers (p?<?0.05).     

Occurrence of ochratoxin A in black pepper, coriander, ginger and turmeric in India

Ochratoxin A (OA) contamination of black pepper, coriander seeds, powdered ginger and turmeric powder was estimated using indirect competitive ELISA. Samples (1 g) were extracted with 0.5% potassium chloride (KCl) in 70% methanol (5 ml) and diluted subsequently to give two-fold to ten-fold step-wise dilutions in phosphate-buffered saline containing 0.05% Tween 20 and 0.2% bovine serum albumin (PBS-T BSA). For extracts from the spices analysed, ELISA estimates of OA concentrations were compared with those made by HPLC. All estimates were within 1-2 standard deviation of the ELISA values. More than 90% of OA added to spice samples was recovered from samples containing between 5 and 100 microg/kg OA. Extracts of OA-free spice samples contained substances that interfered with ELISA, presumably because of non-specific reactions. This effect was avoided by preparing all the test solutions in extracts of OA-free spice samples. In 126 samples obtained from retail shops, OA was found to exceed 10 microg/kg in 14 (in the range of 15-69 microg/kg) of 26 black pepper samples, 20 (in the range of 10-51 microg/kg) of 50 coriander samples, two (23 microg/kg and 80 microg/kg) of 25 ginger samples and nine (in the range of 11-102 microg/kg) of 25 turmeric samples. This is the first record in India of the occurrence of OA in what are some of the most widely used spices in Indian cooking.     

稻米中黄曲霉毒素和赭曲霉毒素A的研究进展

真菌毒素是由某些丝状真菌产生的有毒代谢产物,在自然界中普遍存在,严重威胁人畜健康。综述了黄曲霉毒素和赭曲霉毒素A的理化性质及危害,在稻米中的污染现状、限量标准及分析方法等方面进行阐述,希望能给真菌毒素的研究提供一些参考。      

Occurrence of aflatoxins and ochratoxin A in Indian poultry feeds

From 1998 to 2001, 216 ingredients intended for incorporation into chicken feed, which included groundnut cake, maize, millets, rice bran, sorghum, soybean, sunflower, and mixed feeds, were assayed for aflatoxins and ochratoxin A contamination using an indirect competitive enzyme-linked immunosorbent assay. Thirty-eight percent of the samples were contaminated with aflatoxins and 6% with ochratoxin A. The incidence scores of aflatoxin contamination in excess of 10 microg/kg were 41 of 95 for maize, 18 of 30 for mixed feeds, 10 of 37 for groundnut, 6 of 29 for sorghum, 5 of 10 for sunflower, 3 of 14 for rice bran, and 1 of 8 for millet. Ochratoxin A contamination, in excess of 10 microg/kg, was found in 9 of 29 sorghum samples, 1 of 27 groundnut samples, 1 of 14 rice bran samples, 1 of 10 sunflower samples, and 2 of 8 millet samples. Ochratoxin A was not found in maize and mixed feeds. None of the three soybean samples contained ochratoxin A. This is the first report, to our knowledge, of co-occurrence of aflatoxins and ochratoxin A in Indian poultry feeds. The results confirm the importance of analysis of ingredients before incorporating them into mixed feeds.     

Natural co-occurrence of ochratoxin A,ochratoxin B and aflatoxins in Sicilian red wines

The natural occurrence of ochratoxin A, ochratoxin B, aflatoxin B₁, aflatoxin B₂, aflatoxin G₁ and aflatoxin G₂ (OTA, OTB, AFB₁, AFB₂, AFG₁, AFG₂) in red wines was investigated by HPLC/FLD after immunoaffinity column clean-up in 57 market samples produced in Sicily (Italy). The results showed a very low incidence of these mycotoxins in analysed samples, confirming the high degree of quality and safety of Sicilian red wines. The results indicated 71.9% and 64.9% positive samples for OTA and OTB respectively, with an average level of 0.13 μg l^–1, well below the European maximum permitted levels (MLs). The aflatoxin most frequently detected in the samples was AFG₁, present in 57.9% of samples, while the other aflatoxins were rarely present. Recovery experiments were carried out on eight mycotoxin-free red wines spiked with OTA, OTB, AFB₁, AFB₂, AFG₁ and AFG₂ at two different levels. The limits of detection (LODs) in wines were 0.02 µg l^–1 for OTA, 0.04 µg l^–1 for OTB, 0.03 µg l^–1 for AFG₁, AFG₂ and AFB₂, and 0.05 µg l^–1 for AFB₁. A good correlation was found, with good performances in term of precision for the method.     

Mycotoxin contamination of animal feedingstuff: detoxification by gamma-irradiation and reduction of aflatoxins and ochratoxin A concentrations

Mycotoxins are fungal secondary metabolites identified in many agricultural products screened for toxigenic moulds. They have been reported to be carcinogenic, teratogenic, tremorogenic, haemorrhagic and dermatitic to a wide range of organisms. With the increasing stringent regulations for mycotoxins imposed by importing countries such as those of the European Union, many cereals that are not safe for human consumption are used in formulations intended for animal feed. Gamma-rays are reported in the scientific literature to destroy ochratoxin A and aflatoxin in food crops and feed. The present study provides preliminary data for establishing the effect of dose of gamma-irradiation, ranging from 0 to 15 kGy, on aflatoxins and ochratoxin A reduction in commercial animal feed. The mycotoxin levels were determined by means of immunoaffinity clean-up (IAC) and HPLC with fluorescence detection (HPLC-FLD). The maximum reductions found at 15 kGy were 23.9%, 18.2%, 11.0%, 21.1% and 13.6% for ochratoxin A, aflatoxin B₁, aflatoxin B₂, aflatoxin G₁ and aflatoxin G₂, respectively. Results showed that the gamma-rays even at 15 kGy were not effective in the complete destruction of ochratoxin A and aflatoxins in the tested feed.     

Survey of aflatoxins in retail samples of whole and ground black and white peppercorns

A total of 126 local and imported samples of commercial white and black pepper in Malaysia were analysed for aflatoxins B₁, B₂, G₁ and G₂ (AFB1, AFB2, AFG1, AFG2) content using high-performance liquid chromatography (HPLC) with a fluorescence detector (FD). An acetonitrile–methanol–water (17 : 29 : 54; v/v) mixture was used as a mobile phase and clean-up was using an immunoaffinity column (IAC). Seventy out of 126 (55.5%) samples were contaminated with total aflatoxins, although only low levels of aflatoxins were found ranging from 0.1 to 4.9 ng g^?1. Aflatoxin B₁ showed the highest incidence of contamination and was found in all contaminated samples. There was a significant difference between type of samples and different brands (p < 0.05). The results showed black peppers were more contaminated than white peppers.     

One-year monitoring of aflatoxins and ochratoxin A in tiger-nuts and their beverages

A sensitive and selective liquid chromatography–triple quadrupole–tandem mass spectrometry (LC–ESI–MS–MS) method was developed for the routine analysis of aflatoxins (AFB₁, AFB₂, AFG₁ and AFG₂) and ochratoxin A (OTA) in tiger nuts and tiger-nut beverage (horchata). A matrix solid phase dispersion was adapted to eliminate lipidic interferences. The solid support was C₁₈, while the elution solvent was acetonitrile. Mean recoveries obtained at two fortification levels were 72–83% and 71–81% for horchata and tiger nut respectively with relative standard deviations (RSDs) <13% and 15% respectively. The LC–MS–MS method allowed quantification and identification at low levels in two matrices. The method was applied for the routine analysis of tiger-nuts and horchata samples collected from different supermarkets of Valencia (Spain) during one year (March 2009–March 2010). A total of 238 samples were analysed and 32 samples were found positives for OTA, AFB₁, AFB₂ and AFG₂.     

Flavour and off-flavour compounds of black and white pepper (Piper nigrum L.) III. Desirable and undesirable odorants of white pepper

 Quantification of 19 odorants and calculation of their odour activity values were together the basis for an aroma model which reflected the odour profile of a white pepper sample having a faecal off-flavour. Omission tests indicated limonene, linalool, α-pinene, 1,8-cineole, piperonal, butyric acid, 3-methylbutyric acid, methylpropanal, and 2- and 3-methylbutanal as key odorants of white pepper. The faecal off-flavour was caused by skatole and was enhanced by the presence of p-cresol. In six samples of white pepper the intensity of the faecal off-flavour paralleled the concentration of both skatole and p-cresol. In the sample with the strongest off-flavour the concentrations amounted to 2.6 mg/kg (skatole) and 12.4 mg/kg (p-cresol).     

Influence of yeast strain on ochratoxin A content during fermentation of white and red must

The aim of this work was to examine whether the yeast strains, responsible for alcoholic fermentation, have an influence on the concentration of ochratoxin A (OTA) in wine. Before the fermentation, OTA was added to musts up to a concentration of about 2 microg/l. OTA content was determined in white and red wines resulting from respective musts and in methanolic extract of the yeast lees (MEL). Data showed a significant reduction of OTA at the end of alcoholic fermentation. However, depending on the yeast strain involved in the fermentation, there was a difference in the content of OTA in the wines. The percentage of OTA removal during the fermentation was between 46.83% and 52.16% in white wine and between 53.21% and 70.13% in red wine. The absence of degradation products suggested an adsorption mechanism. OTA concentration in MEL resulting from red must fermentation was higher than in white. A significant amount of OTA was not recovered either from wine or from MEL.     

Surveys of rice sold in Canada for aflatoxins, ochratoxin A and fumonisins

Approximately 200 samples of rice (including white, brown, red, black, basmati and jasmine, as well as wild rice) from several different countries, including the United States, Canada, Pakistan, India and Thailand, were analysed for aflatoxins, ochratoxin A (OTA) and fumonisins by separate liquid chromatographic methods in two different years. The mean concentrations for aflatoxin B(1) (AFB(1)) were 0.19 and 0.17 ng g(-1) with respective positive incidences of 56% and 43% (≥ the limit of detection (LOD) of 0.002 ng g(-1)). Twenty-three samples analysed in the second year also contained aflatoxin B(2) (AFB(2)) at levels ≥LOD of 0.002 ng g(-1). The five most contaminated samples in each year contained 1.44-7.14 ng AFB(1) g(-1) (year 1) and 1.45-3.48 ng AFB(1) g(-1) (year 2); they were mostly basmati rice from India and Pakistan and black and red rice from Thailand. The average concentrations of ochratoxin A (OTA) were 0.05 and 0.005 ng g(-1) in year 1 and year 2, respectively; incidences of samples containing ≥LOD of 0.05 ng g(-1) were 43% and 1%, respectively, in the 2 years. All positive OTA results were confirmed by LC-MS/MS. For fumonisins, concentrations of fumonisin B(1) (FB(1)) averaged 4.5 ng g(-1) in 15 positive samples (≥0.7 ng g(-1)) from year 1 (n = 99); fumonisin B(2) (FB(2)) and fumonisin B(3) (FB(3)) were also present (≥1 ng g(-1)). In the second year there was only one positive sample (14 ng g(-1) FB(1)) out of 100 analysed. All positive FB(1) results were confirmed by LC-MS/MS.     

Occurrence of aflatoxins, ochratoxin A, and fumonisins in retail foods in Japan

We conducted a survey of aflatoxin B1, B2, G1, and G2, ochratoxin A, and fumonisin B1, B2, and B3 contamination in various foods on the retail market in Japan in 2004 and 2005. The mycotoxins were analyzed by high-performance liquid chromatography, liquid chromatography-mass spectrometry, or high-performance thin-layer chromatography. Aflatoxins were detected in 10 of 21 peanut butter samples; the highest concentration of aflatoxin B1 was 2.59 microg/kg. Aflatoxin contamination was not found in corn products, corn, peanuts, buckwheat flour, dried buckwheat noodles, rice, or sesame oil. Ochratoxin A was detected in oatmeal, wheat flour, rye, buckwheat flour, green coffee beans, roasted coffee beans, raisins, beer, and wine but not in rice or corn products. Ochratoxin A concentrations in contaminated samples were below 0.8 microg/kg. Fumonisins were detected in popcorn, frozen corn, corn flakes, and corn grits. The highest concentrations of fumonisins B1, B2, and B3 in these samples were 354.0, 94.0, and 64.0 microg/kg, respectively.     

胡椒幼果与黑、白胡椒香气成分的比较研究

为比较胡椒幼果与黑、白胡椒香气成分的差异,按照L9(34)正交实验设计,通过超声波处理提取胡椒幼果、黑胡椒和白胡椒的胡椒油树脂,再采用GC-MS测定比较其香气成分。结果表明:胡椒幼果油树脂中分离出25种物质,鉴定出20种;黑、白胡椒油树脂中均分离出28种物质,鉴定出23种;胡椒油树脂香味成分主要是α-蒎烯、β-蒎烯、3-蒈烯、D-柠檬油精、4-乙烯基-4-甲基-3-(1-甲基乙烯基)环己烯、石竹烯和胡椒碱等;胡椒幼果具有比黑、白胡椒更为清新、丰满的香气,油树脂得率最高,且其香气成分的相对含量只是略低于黑胡椒和白胡椒,因此可用胡椒幼果油树脂代替黑、白胡椒油树脂开发新型胡椒类产品。     

Validation data for HPLC/FLD determinations of ochratoxin A in red paprika and black pepper adopting a one-step clean-up procedure

Validation data for the determination of ochratoxin A (OTA) in two spice matrices, red paprika and black pepper, were obtained for samples prepared with a simplified single-step clean-up column. Extracts of finely ground samples of red paprika and black pepper were prepared and applied to a Mycosep® 229 Ochra clean-up column. The purified extract was then subjected to HPLC/FLD analysis. The relative standard deviation for repeatability (RSDr) of the method was 11.8% for red paprika and 9.9% for black pepper. The limit of detection (LOD) value (three times the noise) was estimated as corresponding to the response of an extract derived from a blank matrix (previously washed) and spiked at 1.0 µg kg^?1. The limit of quantitation (LOQ) (three times LOD) was 3.0 µg kg^?1. The performance of the one-step column clean-up procedure appears to be a suitable alternative to commonly used clean-up techniques and allows the precise determination of OTA in two complex matrices.     

Effect of berry maturation on some chemical constituents of black, green and white pepper (Piper nigrum L.) from three cultivars

The accumulation pattern of three commercially important constituents (starch, nonvolatile ether extract and piperine) in black, green and white pepper products of a local Sri Lankan cultivar has been compared with that for the Panniyur and Kuching cultivars introduced from India and Sarawak respectively. The local cultivar contained a higher level of starch and lower levels of non-volatile ether extract and piperine than the other two cultivars. The local cultivar has a composition satisfactory for its use in the whole berry form or for processing into a powdered spice.     

Mycological survey for potential aflatoxin and ochratoxin producers and their toxicological properties in harvested Brazilian black pepper.

A mycological survey was carried out on 115 samples of whole dried black pepper seeds, from two main production regions of Brazil (Pará and Espírito Santo). A high incidence of contamination was verified in both regions when 99.1% of the samples showed filamentous fungi contamination. A total of 497 species of nine different genera were isolated (Aspergillus, Eurotium, Rhizopus, Penicillium, Curvularia, Cladosporium, Absidia, Emericella and Paecilomyces). The genus Aspergillus was the predominant (53.5%) followed by species from the Eurotium genus (24.5%). Eurotium chevalieri (16.4%) was the most predominant species followed by A. flavus (14.6%) present on 55 samples of black pepper (47.8%) analysed. Twenty-five samples (21.7%) were contaminated with aflatoxigenic strains of A. flavus and A. parasiticus. In relation to the types of aflatoxins produced by mycotoxigenic strains, it was observed that 25 strains (44.6%) of 56 isolated of A. flavus produced aflatoxins. From 12 samples, A. ochraceus species were isolated in low frequency (3.5%). Two strains of A. ochraceus from 16 isolated were producers of ochratoxin A. With respect to the aflatoxins and ochratoxin A natural contamination, none of the samples presented detectable levels of these mycotoxins using thin-layer chromatographic analysis.     

Occurrence of ochratoxin A in cocoa by-products and determination of its reduction during chocolate manufacture

This work reports an investigation carried out to assess the natural occurrence of ochratoxin A in 168 samples from different fractions obtained during the technological processing of cocoa (shell, nibs, liquor, butter, cake and cocoa powder) and the reduction of ochratoxin A during chocolate manufacture. Ochratoxin A analyses were performed with immunoaffinity columns and detection by high performance liquid chromatography. Concerning the natural ochratoxin A contamination in cocoa by-products, the highest levels of ochratoxin A were found in the shell, cocoa powder and cocoa cake. The cocoa butter was the least contaminated, showing that ochratoxin A seems to remain in the defatted cocoa solids. Under the technological conditions applied during the manufacture of chocolate in this study and the level of contamination present in the cocoa beans, this experiment demonstrated that 93.6% of ochratoxin A present in the beans was reduced during the chocolate producing.     

A review on conventional and biotechnological approaches in white pepper production

White pepper is the dried seeds obtained from pepper berries (Piper nigrum L.) after the removal of the pericarp. It has been widely used as seasoning and condiments in food preparation. Globally, white pepper fetches a higher price compared to black pepper due to its lighter colour, preferable milder flavour and pungency. Increasing global demand of the spice outpaced the supply as the conventional production method used is laborious, lengthy and also not very hygienic. The most common conventional method is water retting but can also include pit soil, chemical, boiling, steaming and mechanical methods. The introduction of a biotechnological approach has gained a lot of interest, as it is a more rapid, convenient and hygienic method of producing white pepper. This technique involves the application of microorganisms and/or enzymes. This review highlights both conventional and latest biotechnological processes of white pepper production. © 2018 Society of Chemical Industry     

Flavour and off-flavour compounds of black and white pepper (Piper nigrum L.) II. Odour activity values of desirable and undesirable odorants of black pepper

Quantification of 14 odorants and calculation of their odour activity values were the basis of an aroma model reflecting most of the odour notes of black pepper. Omission tests indicated α- and β-pinene, myrcene, α-phellandrene, limonene, linalool, methylpropanal, 2- and 3-methylbutanal, butyric acid and 3-methylbutyric acid as key odorants. A storage experiment revealed that for ground black pepper, losses of α-pinene, limonene and 3-methylbutanal were mainly responsible for deficits in the pepper-like, citrus-like, terpene-like and malty notes after 30?days at room temperature. The musty/mouldy off-flavour of a sample of black pepper was caused by a mixture consisting of 2,3-diethyl-5-methylpyrazine (2.9?μg/kg) and 2-isopropyl-3-methoxypyrazine (0.2?μg/kg).