Determination of Patulin Content in Apple Fruits and Some of its Processed Products and Make some Modifications for the possibility of its reduction

Tahani Ahmad Al-Hadad
General Commission for Scientific Agricultural Research- Department of Food Technology,
Faculty of Agriculture,Damascus University,
2013

Abstract

      Apples and its products are the most important sources of patulin     exposure, because of the high rate of its consumption in the recent years. This research aimed to survey the content of patulin in apple products (fruit, juice and baby food) which sold in Damascus and Damascus   countryside, on the other hand, to study the influence of apple juice processing steps, additives (ascorbic acid, sulfur dioxide, cysteine,    quercetin) and carbon filtration on patulin level of juice.

The study examined 20 samples of different apples (different species and quality grade), 20 samples of juice (different bands), and 10 samples of baby food which prepared from apple sauce without or with other        additives.

Patulin was analyzed by using (HPLC-UV) with the following         conditions: temperature of the column was 25 ْC, flow rate was 1 ml/min, wavelength was 276 nm. The results showed that the recovery rate of    patulin in the used method was 83.1%, 85%, 80.3% for fruit, juice and baby food respectively, the linearity was (r2=0.97) in concentrations    (50-250) µg/l, the limit of detection (LOD) was 30 µg/l, and the limit of quantitative (LOQ) was 100 µg/l.

The content of patulin in samples of fresh apple ranged from ND (Non Detected) to 183.2 µg/l, with average of 48.68 µg/l. The number of   samples which patulin exceeded the accepted limit of WHO (50 µg/l) was 10 samples (50%). The patulin content in apple juice samples ranged from ND to 820 µg/l, with an average of 211.15 µg/l, 70% of studied samples exceeded (50 µg/l). The patulin content of baby food samples ranged from ND to 81.5 µg/l, with an average of 20.46 µg/l, 30% of  samples were out of allowed limit (10 µg/l).

Results of studying juice processing stages showed that processing    reduce the content of patulin from fruit up to 79.2%, and the most          significant stage for the reduction of patulin was washing and sorting (41.1%), followed by the enzymatic treatment (10.3%), microfiltration (7.5%), pressing (6.7%), pasteurization (3.4%), and milling (1.8%).

Filtration of final juice (injected with 1500 µg/l patulin) by activated carbon reduced the concentration of patulin from 1225.6 µg/l to below LOD. This treatment influenced negatively on juice color and smell     quality. On the other hand, chemical additives varied in their ability to destroy patulin. Addition of ascorbic acid in concentration of 100 and 500 ppm reduced the concentration of patulin to 940.1 µg/l and ND             respectively, meanwhile, the addition of sulfur dioxide, cysteine, and quercetin in concentration 50 and 100 ppm reduced patulin to 820.7 µg/l and 530.8 µg/l, 975.3 µg/l and 686.9 µg/l, and 1083 µg/l and 850.9 µg/l respectively.

The results showed that the best treatment for reduction of patulin from the final juice product without affecting it’s quality was the addition of ascorbic acid with concentration 500 ppm or quercetin 100 ppm, followed by cysteine and quercetin. Although the addition of sulfur dioxide was effective in destroy patulin, but it maybe decrease juice quality.