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.

Activated Carbons: In Vitro Affinity for Aflatoxin B1 and Relation of Adsorption Ability to Physicochemical Parameters.

Affinity in vitro tests were conducted of the efficacy of 17 activated carbons (ACs) in binding aflatoxin B1 from solution. Relationships between adsorption ability and physicochemical parameters of the ACs (surface area, iodine number, methylene blue index, and surface acidity) were tested. Using 5 ml of a 4 µg/ml aqueous solution of aflatoxin B1 and 2 mg of an AC, adsorption abilities ranged from 44.47% to 99.82%. Four ACs showed very high adsorption abilities, binding more than 99% of the available aflatoxin B1. In comparative testing five ACs showed a greater ability to bind aflatoxin B1 than hydrated sodium calcium aluminosilicate (HSCAS). Three ACs also showed high adsorption abilities (ca. 99%) at increasing aflatoxin B1 concentrations (50 and 250 µg/ml) whereas HSCAS adsorption ability greatly declined. With the exception of three ACs, aflatoxin B1 adsorption was significantly correlated with all the physicochemical parameters, confirming a close relationship between molecule trapping and the surface physicochemical adsorption process. The methylene blue index was more reliable than iodine number and surface area in predicting AC adsorptive ability. The results suggested that ACs with a high methylene blue index and low surface acidity have a very high in vitro affinity for aflatoxin B1; however, their efficacy in protecting against aflatoxicosis should be verified further by in vivo tests.

Activated Carbons: In Vitro Affinity for Fumonisin B1 and Relation of Adsorption Ability to Physicochemical Parameters.

In vitro affinity tests were conducted to assess the effectiveness of 19 activated carbons (ACs), hydrated sodium calcium aluminosilicate (HSCAS), and sepiolite (S) in binding fumonisin B1 (FB1) from solution. Relationships between adsorption ability and physicochemical parameters of ACs (specific surface area, iodine value, and methylene blue index) were tested. When 5 ml of a 4-µg/ml aqueous solution of FB1 was treated with 10 mg of AC, ACs adsorbed 0.46 to 100% of the FB1. HSCAS and S were not effective in binding FB1. In two saturation tests carried out with decreased amounts of sorbent (5 and 2 mg, respectively), three ACs also showed high adsorption ability (adsorbing 96.48 to 99.20% of the FB1) A general relationship between adsorption ability and the physicochemical parameters of the ACs was observed, supporting the inference of a close relationship between molecule trapping and surface physicochemical adsorption processes. The methylene blue index was more reliable than iodine number and surface area for predicting ability of ACs to adsorb FB1. In tests of simultaneous adsorption ability carried out using 5 ml of a solution containing 10 µg/ml FB1 plus 50 µg/ml aflatoxin B1 (AFB1)and 2 or 5 mg of sorbent, ACs showed a higher affinity for AFB1 than for FB1. However, two ACs bound ca. 100% of the two mycotoxins. When 5 ml of an aqueous extract solution obtained from naturally contaminated corn containing 1.84 µg/ml FB1 and 0.042 µg/ml AFB1 was treated with 10 mg of sorbent, one AC adsorbed ca. 95% and 99% of FB1 and AFB1, respectively. It is concluded that certain ACs have high in vitro affinity for FB1 and AFB1 singly or in combination, and may hold promise as multi-mycotoxin sequestering agents. However, further in vivo investigations are neededto confirm the abilities of ACs to sequester the most important mycotoxins singly or in combinations, establish the amounts to be added to feeds, and determine any long-term effects they may have on gastrointestinal absorption of essential nutrients.