In an article published on April 5, 2023, in the journal Environmental Science & Technology, Bibai Du and co-authors from Jinan University, Guangzhou, China, analyzed antioxidants in baby food available in China and their sources. Specifically, the researchers were interested in traditional synthetic phenolic antioxidants, such as butylated hydroxytoluene (BHT, CAS CAS 128-37-0), butylated hydroxyanisole (BHA), 2,4-di-tert-butylphenol (DBP, CAS96-76-4), and 2,4,6-tri-tert-butylphenol (AO 246, CAS732-26-3 ), as well as their “novel” counterparts such as pentaerythritol tetrakis[3- (3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (AO 1010, CAS 6683-19-8), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (AO 1076, CAS 2082-79-3).
Antioxidants are used in a variety of consumer products, including food packaging, to prevent oxidation and prolong a product’s lifetime. Some of them, such as BHT, have been shown to negatively impact human health, e.g, resulting in endocrine disruption and developmental toxicity.
Du and co-authors analyzed 45 infant formulas, 28 cereal, and 26 puree samples for the presence of 19 novel and seven traditional synthetic phenolic antioxidants and four related transformation products using liquid chromatography−tandem mass spectrometry (LC−MS/MS). They reported BHT to be the most prevalent, followed by DBP, AO 1010, and AO 1076. The common migration of BHT from plastic products is confirmed by previous studies (FPF reported and here). Comparing total levels of traditional antioxidants with novel antioxidants, Du and colleagues found median concentrations of novel antioxidants to be higher in all three types of baby foods. Concentrations of the novel compounds were 604, 218, and 24.1 ng/g, in infant formula, cereal, and puree samples, respectively, while those of traditional antioxidants were 53.4, 62.1, and 10.0 ng/g.
To assess if the chemicals originated from the plastic food packaging, the scientists also investigated the presence (extraction with dichloromethane/n-hexanehexane) and migration (using the food simulant Tenax) of four selected antioxidants. All four compounds, BHT, DBP, AO 1010, and A 1076 were detected in the majority of the 54 investigated plastic bags. AO 1076 was present in the highest median concentration of 34,500 ng/g followed by A 1010 with 7130 ng/g. Migration was monitored over 60 days from one plastic bag containing high levels of the chemicals. All four antioxidants migrated into the food simulant. Rates decreased with the increase of the molecular weight of the respective compound: DBP > BHT > AO 1010 > AO 1076. Based on their one sample, the authors concluded that migration rates were generally low. However, they further pointed out that antioxidants may undergo transformation processes (e.g., photodegradation) during migration which could result in even more toxic products. These would need further assessment.
Estimating infant exposure, the authors reported that “there may be no appreciable health risk posed by the synthetic phenolic antioxidants in baby food.” However, it is “still a dominant pathway for infant exposure to synthetic phenolic antioxidants, with a higher contribution than breast milk consumption, dust ingestion, dermal dust absorption, and air inhalation, which requires special attention.”
Other plastic additives besides antioxidants have been detected in baby foods such as phthalate esters (FPF reported).
In an article published earlier in 2023 in the journal Food Packaging and Shelf Life, Hyung Soo Kim and co-authors from Korea University, Seoul, assessed the migration of antioxidants and their degradation products from 142 food contact items acquired in Korea and made of 18 synthetic resins. Migration experiments were performed under various conditions studying the influence of different food simulants, temperatures, ultraviolet exposure, and microwave use.
The researchers targeted 36 substances in their chemical analysis. Of these, DPB was most commonly detected, and its migration was the highest when the food contact material was used for the first time. Also, 1,3 di-tert-butylbenzene (CAS 1014-60-4), the major degradation product of Irgafos 168 (CAS 31570-04-4), was frequently detected. Comparing different food simulants, the authors reported that migration was highest in those simulating fatty foods, especially isooctane. Their risk assessment using the threshold of toxicological concern (TTC) approach showed that the migration of individual substances was below their toxicity reference values. However, the picture can change when looking at cumulative risks. “In particular, oxidized Irgafos 168, (z)-9-octadecenamide (L3, G16), 7,9-di-tert-butyl-1-oxaspiro(4,5)deca-6,9-diene-2,8-dione (G13), tri-otolyl phosphite (G24), and tri-p-tolyl phosphite (G25) showed high cumulative risks when TTC was applied,” the authors reported.
References
Du, B. et al. (2023). “Prevalence of Novel and Traditional Synthetic Phenolic Antioxidants in Baby Food from China: A Dominant Pathway for Infant Exposure.” Environmental Science & Technology. DOI: 10.1021/acs.est.3c00079
Kim, H. S. et al. (2023). “Comparison of migration and cumulative risk assessment of antioxidants, antioxidant degradation products, and other non-intentionally added substances from plastic food contact materials.” Food Packaging and Shelf Life. DOI: 10.1016/j.fpsl.2023.101037
