Gianfranco Piva

Climate change and food safety: An emerging issue with special focus on Europe

According to general consensus, the global climate is changing, which may also affect agricultural and livestock production. The potential impact of climate change on food security is a widely debated and investigated issue. Nonetheless, the specific impact on safety of food and feed for consumers has remained a less studied topic. This review therefore identifies the various food safety issues that are likely to be affected by changes in climate, particularly in Europe. Amongst the issues identified are mycotoxins formed on plant products in the field or during storage; residues of pesticides in plant products affected by changes in pest pressure; trace elements and/or heavy metals in plant products depending on changes in their abundance and availability in soils; polycyclic aromatic hydrocarbons in foods following changes in long-range atmospheric transport and deposition into the environment; marine biotoxins in seafood following production of phycotoxins by harmful algal blooms; and the presence of pathogenic bacteria in foods following more frequent extreme weather conditions, such as flooding and heat waves. Research topics that are amenable to further research are highlighted.

Occurrence of ochratoxin A in Italian wines

A total of 96 red wines and 15 white dessert wines produced mostly in the years 1995–97 in 19 Italian regions were analysed for ochratoxin A (OTA). The amount of OTA ranged from < 1 to 3856 ng/l, the median (mean) was found to be 90 (419)ng/l for the red wines and 8 (736)ng/l for the white dessert wines. Our survey shows that the geographic region of origin has a strong influence on OTA contamination, both for red and for dessert wines: in fact, wines produced in southern Italy were markedly more contaminated. The overall median (mean) OTA concentration in the red wines produced in the four Italian areas (northwest, northeast, centre and south) was 2 (11), 90 (81), 134 (295) and 1264 (1233)ng/l. The same trend was observed for the white dessert wines: OTA concentrations of over 1000ng/l were found in four out of five samples from southern Italy (1185, 2454, 3477, 3856ng/l), while central and northern samples showed very low contamination. The contribution of wine to mean daily OTA intake can be considered negligible in the case of people drinking wine manufactured in northern and central Italy; this is not true if a medium drinker constantly consumes red wine produced in southern Italy: in this case wine alone could supply the diet with an amount of OTA equal to or even above the tolerable daily intake of 5ng/kg body weight recommended by the Scientific Committee on Food of the European Commission.

Occurrence of mycotoxins and ergosterol in maize harvested over 5 years in Northern Italy

Maize samples collected from storage bins and feed mills in Northern Italy between 1995 and 1999 were surveyed for the occurrence of aflatoxin B1 (AFB1), zearalenone (ZEA), deoxynivalenol (DON) and fumonisin (FB1); further, ergosterol was analysed as a fungal growth marker. The incidence and mean content of AFB1 were generally low; nevertheless, a remarkable contamination was found in two samples (109 and 158 μg kg−1), while five others exceeded 20 μg kg−1. DON and ZEA mean levels were significantly higher in 1996 (2716 and 453 μg kg−1) with respect to the other years, when mean contents ranged from 7 to 30% and from 3 to 17%, respectively, expressed in per cent of 1996 contents. FB1 was present in all samples and was by far the most remarkable mycotoxin in Northern Italian maize, with the exception of samples from 1996. The average level was 3064 μg kg−1, 69.6% of samples resulted over 1000 μg kg−1 and 16.9% over 5000 μg kg−1. Significant correlations were found between ergosterol and the major mycotoxin(s) in each year (FB1 in 1995 and 1997–99; ZEA + DON in 1996). Consequently, ergosterol seems to be a good index of the toxicological quality of maize. Climatic conditions influenced the growth of different fungal species. In 1996, the first 20 days of October were extremely rainy; these weather conditions delayed the harvest until the first week of November and favoured the growth of DON and ZEA producing fungi and the synthesis of mycotoxins. On the contrary, the temperate and dry climate of the other years supported the growth of FB1-producing fungi.

DETOXIFICATION METHODS OF AFLATOXINS. A REVIEW.

Detoxification of aflatoxin contaminated foods and feeds is a current problem, as aflatoxins are highly carcinogenic and capable of passing unaltered through metabolic processes and accumulating in the tissues (seriously jeopardizing human and animal health). Although numerous detoxification methods have been tested, none seems able to fulfill the efficacy, safety, safeguarding of nutritional elements and costs requisites of a detoxification process. This paper critically reviews the main chemical detoxification methods and the latest approach to the problem using added sorbents capable of adsorbing aflatoxins.

Carryover of aflatoxin from feed to milk in dairy cows with low or high somatic cell counts

Aflatoxin M1 (AFM1) residues in milk are regulated in many parts of the world and can cost dairy farmers significantly due to lost milk sales. Additionally, due to the carcinogenicity of this compound contaminated milk can be a major public health concern. Thirty-four lactating dairy cows were utilised to investigate the relationship between somatic cell counts (SCC), milk yield and conversion of dietary aflatoxin B1 (AFB1) into milk AFM1 (carryover (CO)). The AFM1 in milk increased as soon as the first milking after animal ingestion with a pattern of increment up to the observed plateau (between 7th and 12th days of AFB1 ingestion). There was a significant (P < 0.01) effect of the milk yield whereas no effect could be attributed to the SCC levels or to the milk yield × SCC interaction. Similarly, the main effect of milk yield was also observed (P < 0.01) on the total amount of AFM1 excreted during the ingestion period. Although the plasma concentration of gamma-glutamyl transferase was significantly affected by aflatoxin administration, levels of this liver enzyme were within the normal range for lactating dairy cows. The current data suggest that milk yield is the major factor affecting the total excretion of AFM1 and that SCC as an indicator of mammary gland permeability was not related to an increase in AFM1 CO.

Reduction of carryover of aflatoxin from cow feed to milk by addition of activated carbons

According to a double-reversal experimental design on 12 late-lactation Friesian cows the effect of two activated carbons (ACs) (CAC1 and CAC2) and a hydrated sodium calcium aluminosilicate (HSCAS) on carryover of aflatoxin B1 (AFB1) from feed to aflatoxin M1 (AFM1) in milk was determined. Cows were fed a basal diet containing AFB1 naturally contaminated corn meal and copra, During week 1 cows were fed diets containing AFB1 alone (11.28 μg of AFB1/kg of feed); in week 2 the diets contained AFB1 plus 2.0% sorbent; and in week 3 the diets again contained AFB1 alone (13.43 μg of AFB1/kg of feed). ACs reduced the analytical content of AFB1 in the pelleted feed by from 40.6% to 73.6%, whereas reduction by HSCAS was 59.2%, The AFM1 concentrations in milk in weeks 1 and 3 were higher than that in week 2, Decreases in the AFM1 excreted in the milk by addition to feed of 2% of the sorbents ranged from 22% to 45%. CAC1 and HSCAS were significantly different from each other in reducing the AFM1concentration in milk (45.3% versus 32.5%); these reductions were significantly higher than that of CAC2 (22.0%). Carryover reduction by addition of CAC1 (50%) was significantly higher than that of HSCAS (36%). Addition of 2% CAC2 did not allow pelleting of feed because of the caking action of this carbon, The lower performance of CAC2 could be related to the unsuccessful pelleting. The addition of ACs did not influence feed intake, milk production, milk composition, or body weight. Our results suggest that ACs, high-affinity sorbents for AFB1 in vitro, are efficacious in reducing AFB1 carryover from cow feed to milk. Further in vivo investigations should establish lower amounts of ACs which can be efficacious.

Aflatoxin M1 occurrence in samples of Grana Padano cheese

A total of 223 samples of Grana Padano cheese manufactured in 4 years (1991-94) by dairies in 11 provinces of the Po valley were checked for aflatoxin M1. Grated cheese was extracted with chloroform and the defatted extract was purified by an immunoaffinity column; aflatoxin M1 was determined by HPLC using a fluorescence detector. From the analysis of the data it has emerged that only one sample exceeded the maximum tolerated level in cheese in some European countries (250 ng/kg). Most samples (91%) were in the range 5-100 ng/kg and only 15 (6.7%) in the range 100-250 ng/kg. Notwithstanding a diffuse microcontamination, the situation regarding the AFM1 levels can be considered fairly satisfactory. Mean contamination levels of 1992 and 1994 were significantly higher (P < 0.05) than those of 1993 and 1991. No significant difference was observed among provinces or dairies of origin.

Pea seeds (Pisum sativum), faba beans (Vicia faba var. minor) and lupin seeds (Lupinus albus var. multitalia) as protein sources in broiler diets: effect of extrusion on growth performance

Abstract The effect of extrusion of pea seeds (Pisum sativum) (PS), faba bean (Vicia faba, variety minor) (FB) and lupin seeds (Lupinus albus, variety multitalia) (LS) on broiler performance were evaluated. Four hundred sixty two 1d-old Ross male chicks, Marek vaccinated, were randomly assigned to seven dietary treatments (3 pens per treatment/22 birds per pen). Chicks were floor housed, ad libitum fed isocaloric and isonitrogenous diets and had free access to water. Artificial light was provided 10 h/d. The bulk of the base diet (control diet) was corn (48.8%, 53.7% and 57%), solvent-extracted soybean meal (42.8%, 37.3% and 33.4%), corn oil (4.4%, 5.2% and 6.3%), plus synthetic amino acids, minerals, trace minerals and vitamins, respectively for the 1-10d-old, 11-28d-old and 29 to 42d-old growing periods. The amounts of PS, FB and LS used on an as fed basis were: PS and extruded PS (EPS): 353 (1-10d-old), 356 (11-28d-old) and 350 (29-42d-old) g/kg; FB and extruded FB (EFB): 479 (1-10d-old), 497 (11-28d-old) and 500 (29-42d old) g/kg; LS and extruded LS (ELS): 360 (1-10d-old) and 300 (11-42d-old) g/kg. High levels of pea (350 g/kg) and faba bean (500 g/kg) did not show negative effects on body weight gain (BWG) and bird feed intake compared to control. Lupin at the 300 g/kg level reduced (P < 0.05) the BWG during the finishing period (22 to 42 d), however the effect disappeared over the whole experimental period (1-42 d) compared to the control group. The ELS group had a lower (P < 0.01) feed intake compared to the control group and to the LS group. The feed conversion rate (FCR) was similar among groups for the whole experimental period; however during the grower period the FCR was higher (P < 0.05) for the PS, FB and EFB groups compared to the control group. Birds consuming the PS diet had a reduced (P < 0.05) eviscerated carcass yield compared to the control group. The breast meat percent yield was higher (P < 0.01) for birds consuming the FB and EFB diets compared to the control group. There were no statistical differences in percent yield of the leg quarters and in blood parameters.

Vaccination of Lactating Dairy Cows for the Prevention of Aflatoxin B1 Carry Over in Milk

The potential of anaflatoxin B1 (AnAFB1) conjugated to keyhole limpet hemocyanin (KLH) as a vaccine (AnAFB1-KLH) in controlling the carry over of the aflatoxin B1 (AFB1) metabolite aflatoxin M1 (AFM1) in cow milk is reported. AFB1 is the most carcinogenic compound in food and foodstuffs amongst aflatoxins (AFs). AnAFB1 is AFB1 chemically modified as AFB1-1(O-carboxymethyl) oxime. In comparison to AFB1, AnAFB1 has proven to be non-toxic in vitro to human hepatocarcinoma cells and non mutagenic to Salmonella typhimurium strains. AnAFB1-KLH was used for immunization of cows proving to induce a long lasting titer of anti-AFB1 IgG antibodies (Abs) which were cross reactive with AFB1, AFG1, and AFG2. The elicited anti-AFB1 Abs were able to hinder the secretion of AFM1 into the milk of cows continuously fed with AFB1. Vaccination of lactating animals with conjugated AnAFB1 may represent a solution to the public hazard constituted by milk and cheese contaminated with AFs.

Aflatoxin M1 occurrence in dairy products marketed in Italy

In 1984, 313 samples of imported liquid milk and 159 samples of imported cheese were checked for aflatoxin M1; 225 of the milk samples came from FR Germany and 88 from France, while 82 of the cheese samples came from France, 34 from FR Germany and 43 from the Netherlands. The number of positive samples was small both for German (13.8%) and for French (12.5%) milks, and the contamination levels were very low (maximum 23 ng/l). As regards the cheeses, aflatoxin M1 was detected in 19.5, 26.5 and 53.5% of the French, German and Dutch samples respectively, but only 2 French samples exceeded 250 ng/kg, the limit set by Swiss law. In 1985, two surveys were carried out on 276 milk samples mostly obtained from individual farms and on 416 cheese samples taken from all parts of the country. As regards the milk samples, 70 (25.3%) contained aflatoxin M1, but generally at very low levels; in fact only 7 (2.5%) of the samples exceeded 50 ng/l. Aflatoxin M1 was found in 130 (31.3%) of the cheese samples, but here again only 9 (2.2%) exceeded 250 ng/kg. There was no significant difference in aflatoxin M1 levels between Italian, German and French cheese samples but these were significantly lower (P less than 0.01) than in Dutch samples.