Residual levels of total sulphur dioxide in dried fruit samples from Belgrade market

Abstract

Sulphiting agents have been used in food production for centuries. Sulphites are added to food as antimicrobial, antibrowning agents or antioxidants. Their use became an issue of concern when certain sensitive individuals exhibited adverse reactions to sulphite residues in foods. Sulphites also exert a number of different anti-nutritive effects. Like other ingredients, sulfites must be declared in the ingredient statement. Among all sulphite-containing foods, the highest contributors to the dietary intake are dried fruits and wine. The aim of this work was to determine residual levels of total sulphur dioxide in dried fruit samples in order to examine the risk of exceeding the Acceptable Daily Intake (ADI) for sulphites by consuming this type of food. The other scope of the study was to investigate compliance with food labeling in order to insure consumer protection. The determination was performed on all samples by colorimetric para-rosaniline method, according to the official method of analysis of AOAC 963.20 (AOAC 2002).Twelve different samples of dried fruit were analyzed. Results showed that dried fruit is very rich source of sulphites. The range of residual sulphur-dioxide was very large, from nondetectable levels (in three samples) to 1847.3 mgSO2/kg. In ten of twelve samples SO2 levels were under national Maximum Permitted Level (MPL). SO2 content was above MPL in dried bananas sample and dried sweet coconut. Just eight of twelve fruit samples had label declarations of sulfite content but the determined levels of sulfites were significantly above the declared levels.

Sulfiti se u različitim hemijskim formama koriste vekovima kao aditivi u proizvodnji hrane. Oni imaju antimikrobno delovanje, koriste se za sprečavanje enzimskog i neenzimskog tamnjenja namirnica i kao antioksidansi. Mogu se javiti i kao prirodni sastojci namirnica. Primenu sulfita kao aditiva ograničava činjenica da konzumiranje hrane koja sadrži sulfite kod određenog broja astmatičara dovodi do pogoršanja simptoma. Veliki broj namirnica sadrži sulfite, ali se smatra da najveći doprinos dnevnom unosu daju vino i suvo voće. Cilj ovog rada je određivanje rezidualnog sumpor-dioksida u uzorcima suvog voća sa beogradskog tržišta. Određivanje je urađeno oficijelnom kolorimetrijskom metodom sa p-rozanilin hidrohloridom AOAC 963.20 (AOAC 2002). Rezultati su pokazali da je suvo voće značajan izvor sulfita i nivo rezidualnog sulfita se kretao od nedektibilnih vrednosti do 1847.3 mg SO2/kg. U dva od analiziranih dvanaest uzoraka, nivo rezidualnog sumpor-dioksida prevazilazio je propisane MDK vrednosti za ove vrste uzoraka. Osam uzoraka suvog voća je imalo deklarisan sadržaj SO2 ali su nadene vrednosti bile znatno veće od deklarisanih. S obzirom na redovnu upotrebu sulfita u proizvodnji suvog voća, može se zaključiti da je neophodno da proizvođači hrane, posebno prerađevina od voća, imaju razvijen sistem kontrole nivoa sulfita u proizvodima koji ce se naći na tržištu kao i obavezu da u saglasnosti sa važećim propisima, prisustvo sulfita bude deklarisano.