ROCZN. PZH, 1996, 47, NR 3
STANISŁAW SADŁO
C H A N G E S O F B R O M O P R O P Y L A T E A N D C A R B E N D A Z IM R E S ID U E S D U R IN G P R O C E S S IN G O F A PPL E S IN T O A P P L E P U R E E
ZMIANY POZOSTAŁOŚCI BROMOPROPYLATU I KARBENDAZYMU W TRAKCIE PRZEROBU JABŁEK NA KREMOGEN JABŁKOWY
Experimental Station of the Institute of Plant Protection, 35-101 Rzeszów, Langiewicza 28 Str., Poland
Head: prof. dr hab. Z. Przybylski
The study o f changes o f bromopropylate and carbendazim residues during apple processing was carried out. It was stated that bromopropylate residues on apples before and after washing stayed at similar levels (0.024 mg/kg) and then dropped by 60% during apple processing, while those o f carbendazim remained at the level o f 0.10 mg/kg during the whole process.
INTRODUCTION
T h e study o f pesticide residues in food has the p ro tectio n o f hum an h ealth as its prim ary objective. B efore a pesticide is p u t on the m arket, it m ust u n d erg o m any toxicological tests to com pletely evaluate th e short- and long-term effects w hich h um an s m ay be exposed to by the presence o f its residues in food. O n th e basis of these studies, th e F A O an d W H O established the A D I (A cceptable D aily In tak e, as mg/kg o f body w eight) which is the am ount o f a certain co m pound th a t a p erso n can ingest during his lifetim e w ithout dam age to his health. D ep en d in g on th e A D I, and taking into account th e am o u n t o f residue-containing food in th e daily diet, co m p eten t a u th o rities establish th e M axim um R esidue Lim it (M R L ) allow ed in foods. A s a rule, th e M R L s concern unprocessed foods. In Poland, however, M R L s at th e level o f 0.01 m g/kg are proposed also fo r all foods destined fo r children. Sim ilar restrictions have b ee n im posed on pesticide residues in baby food in G erm any.
T h e aim o f th e study was to estim ate if brom opropylate and carbendazim residues, p re se n t in apples as a result o f chem ical treatm en t, d ro p p ed during apple processing to th e rigorous level o f 0.01 mg/kg in th e final products.
MATERIALS AND METHODS P e s t i c i d e s t e s t e d .
Investigation included active ingredients (a.i.) o f agricultural chem icals, which, according to grow er's inform ation, w ere used in fruit trees' protection: N eo ro n 500 E C (acaricide, a.i.-brom opropylate), applied on 7 M ay and 21 Ju n e and B enlate (fungi cide, a.i.-benom yl), applied also twice on 22 July and 18 A ugust. T ests w ere conducted
274 S. Sadło N r 3
during apple processing into apple p u ree on 12 D ecem ber, after a tw o-m onthly period of storage of the apples.
A p p l e p r o c e s s i n g d e s c r i p t i o n .
A fte r washing, apples w ere sorted on an inspection conveyer belt w ith w ater spray, ground in R ietz mill and then steam ed in a finisher w ith sieve m esh d ia m e te r 1.2 mm and 0.4 mm. A fte r d e aera tio n and rapid pasteurization at 96-100°C w ithin 60-90 sec onds, apple p u ree was cooled down to 8-10°C and then frozen.
S a m p l i n g .
Sam ples w ere collected in specified below apple p u ree p roduction stages:
— apples before washing (5 sam ples o f raw fruits collected at ran d o m from various p arts o f several containers),
— w ashed apples (5 sam ples of fruits taken at 20-m inute intervals from inspection conveyer belt) and,
— apple p u ree (5 sam ples taken at 20-m inute intervals from a tank a fte r cooling). E x t r a c t i o n p r o c e d u r e .
100 g apple o r apple p u ree subsam ples w ere hom ogenized with 180 ml o f aceto n e and then pesticide residues w ere extracted with dichlorom ethane, according a m ul tiresidue m ethod [1, 2]. T h e final extract (10 ml), equivalent to 20 g o f th e sam ple, was analyzed w ith th e aid o f a G as-C hrom atograph equ ip p ed with an electro n cap tu re d e te c to r on a colum n with 3% of O V 101 on G as-C hrom Q 100-120 m esh and results obtain ed w ere then confirm ed on a colum n w ith mixed stationary phase O V 17 + Q F 1. A fter determ in atio n of brom opropylate residues, the extracts w ere c o n cen trated to th e volum e of 2 ml and carbendazim residues w ere estim ated with T hin Layer C h rom atography [3].
RESULTS AND DISCUSSION
Benom yl, closely related to th io p h an ate methyl (T opsin M 70 W P), is a benzim i- dazole com pound used as a curative, preventive, and systemic fungicide, very effective against diseases occurring on apples in storage. F o r this reason th e com pound, fo rm u lated as B enlate, is widely em ployed in apple orchards 2-3 w eeks b efo re harvest at the ra te o f 1.5 kg/ha. T he biological activity o f B enlate is m ainly due to carb e n dazim , into which its active ingredient is rapidly converted with the decrease o f m olecular w eight by 35% . In a m onitoring survey conducted betw een 1985 and 1989, it was rep o rte d th a t carbendazim residues w ere p resen t in 45% o f sam ples o f fresh apples [4]. In 5% o f the sam ples, they exceeded 0.1 mg/kg, a level sim ilar to those d etected in apples used in the study. B rom opropylate is a new contact acaricide used both in greenhouses and outdoors. In apple orchards, the chem ical is applied for the control o f the m obile stages o f phytophagous m ites at the rate o f 1.1-1.5 1/ha.
F rom the d a ta rep o rte d in T able I it can be seen that carbendazim and b ro m o propylate residues in raw, unprocessed apples after two sprayings w ere, on average, 0.10 and 0.024 mg/kg, respectively. D ifferences betw een th eir values may be linked to different preharvest intervals which elapsed from the last treatm en ts. H ow ever, their presence in apples a fter such a long period o f tim e indicated th at the two com pounds are persistent ones. A fter washing, their average residues stayed at sim ilar levels what
N r 3 Pozostałości pestycydów w jabłkach 275 additionally proved th a t brom opropylate, though nonsystem ic com pound, is strongly absorbed on th e fruit surfaces. In the apple p u ree carbendazim residues rem ained unchanged b u t co n cen tratio n o f brom opropylate decreased by 60% . H ow ever, the d ecrease o f bro m o p ro p y late residues does not m ean th a t th e com pound undergoes d egradiation during apple processing because the apple skins retain ed on the sieves w ere n o t analyzed.
T a b l e I . Bromopropylate and carbendazim residues (mg/kg)* in apples and apple puree Pozostałości bromopropylatu i karbendazymu w jabłkach i kremogenie jabłko wym
* The reported values are residue ranges and their average levels ± standard deviations of duplicate analyses from five replications.
A fter w ashing the apples to elim inate im purities, processing m ethod com prised grinding and steam ing, follow ed by pressing, w hereby p u ree was sep arated from the skin (ab o u t 10% o f the to tal mass o f apples used). O n an average, 0.3 kg of apple p u re e is n eed ed to pro d u ce 1 litre of juice, and th erefo re any pesticide residues, if com pletely tran sferred from the apples to the p u ree, can u ndergo about a 3-fold dilution in juice. T h e d a ta re p o rted in T able I indicated th a t carbendazim behave in this way. H ence, apples supplied from orchards sprayed with B enlate o r Topsin 2-3 w eeks b efore harvest should be carefully checked for carbendazim residues b e cause apple processing do not ensure reduction of its am ount in the final product, even after 3-fold dilution, as it takes place in the case o f juice p roduction, carbendazim residues may exceed the level o f 0.01 mg/kg. A pples, com ing from orchards in which N eoron was applied should be also analyzed on the presence o f brom opropylate. H ow ever, d ue to a longer preharvest interval and reduction o f its c o n ten t in fresh apples during apple processing, it is alm ost im possible for brom opropylate residues in apple p u re e to exceed th e level of 0.01 mg/kg.
S . S a d ł o
ZMIANY POZOSTAŁOŚCI BROMOPROPYLATU I KARBENDAZYMU W TRAKCIE PRZEROBU JABŁEK NA KREMOGEN JABŁKOWY
S t r e s z c z e n i e
Celem badań było sprawdzenie czy pozostałości bromopropylatu i karbendazymu spadną w produktach końcowych poniżej poziomu 0,01 mg/kg. Przeprowadzono je 12 grudnia, po dwumiesięcznym przechowywaniu jabłek. Próby jabłek przed i po myciu oraz kremogenu po
276 S. Sadło N r 3 schłodzeniu homogenizowano z acetonem a następnie pozostałości pestycydów ekstrahowano dwuchlorometanem. Ekstrakt końcowy analizowano za pomocą chromatografu gazowego wy posażonego w detektor wychwytu elektronów a po oznaczeniu bromopropylatu zawartości kar- bendazymu określano metodą chromatografii cienkowarstwowej. Pozostałości karbendazymu i bromopropylatu w nie przetworzonych jabłkach po dwukrotnych opryskach wyniosły średnio 0,10 i 0,024 mg/kg i po myciu nie uległy zmianie. W kremogenie jabłkowym pozostałości karbendazymu utrzymały się także na niezmienionym poziomie podczas gdy stężenie bromo propylatu obniżyło się o 60%. Uzyskane wyniki wskazują, że jabłka dostarczane z sadów chronionych preparatami Benlate i Neoron 500 EC powinny być dokładnie przebadane na zawartości karbendazymu i bromopropylatu. Pozostałości karbendazymu, nawet po trzykrotnym rozcieńczeniu kremogenu jabłkowego podczas produkcji soków, mogą przekraczać poziom 0,01 mg/kg.
REFERENCES
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