Two novel synthetic antioxidants for deep frying oils
Introduction
Butylated hydroxytoluene (BHT), butylated hydroxyanisol (BHA), tert-butylated hydroquinone (TBHQ) and propyl gallate are the most widely used antioxidants in the food industry, especially for oils and fatty foods. These synthetic antioxidants are highly active and cheap. They are colourless, odourless and tasteless, but they are generally active only at low temperature. However, at high temperature, such as in deep frying and baking at 150–200 °C, these compounds are ineffective. At high temperatures, BHA, BHT and TBHQ are evaporated with steam and PG decomposes particularly when a large quantity of water is expelled from foods during frying or baking. (Lee & Kim, 1979, Kim & Pratt, 1990, Warner et al., 1986).
The frying oils are easily autoxidized at high temperatures and partly polymerized and partly decomposed on oxidizing at high temperature if adequate antioxidants are not present. The oils become viscous and darkened; nutritional components, such as VE, VA, VK, VD and essential fatty acids in the frying oils, are destroyed quickly (Weng, 1993). Moreover, foods fried in oxidized oil can develop an unpleasant flavour. The shelf lives of fried foods are short and might develop off-flavours if sufficient amounts of antioxidant do not remain in the foods after frying (Yagi, 1988).
Effective antioxidants, for deep frying of oils, are very important in practice. In this paper, two antioxidants, synthesized from TBHQ and n-lauryl alcohol for deep frying oils are reported and their antioxidant activity is investigated.
Section snippets
Materials
Lard was rendered in the laboratory and stored in a deep freezer for use. Soy oil was purchased from Shanghai Oil and Fat Co. (Shanghai, China). TBHQ, BHA, BHT and Tween 20 were purchased from Shanghai Chemical Reagent Co. (Shanghai, China). Other chemicals used in this experiment were all AR grade and from this company. Silica gel was from Qingdao Chemical Factory (Qingdao, China).
Synthesis and purification of the compounds
A mixture of TBHQ (5 g, 30 mmol) and n-lauryl alcohol (5.6 g) was added to 85% phosphoric acid (1.7 g). The
Results and discussion
Lauryl tert-butylate hydroquinone (LTBHQ) and lauryl tert-butylated quinone (LTBQ) were synthesized from n-lauryl alcohol and TBHQ. Phosphoric acid (0.5 mol/mol TBHQ) was used as catalyst. The mixture of TBHQ and lauryl alcohol (1:1, mol/mol) were refluxed in toluene (200 ml/mol TBHQ) for 6.5 h. The yields were 16.0±0.8% for LTBHQ and 6.1±0.9% for LTBQ.
The lauryl group can attach at the 5- or 6-position of TBHQ, but the 5-isomer may be slightly more than the 6-isomer, because the 5-position is
Acknowledgements
The authors thank the Natural Science Foundation Commission of China for the research grant (approval number: 20242007).
References (8)
- et al.
Interfacial phenomena in the evaluation of antioxidantsbulk versus emulsion
Journal of Agricultural and Food Chemistry
(1994) - et al.
Degradation products of 2-tertylhydroquinone at frying temperature
Journal of Food Science
(1990) - et al.
Variation of antioxidant retention and some properties of soybean oil during simulated frying operation
Hanguk Sikp'um Kwahakhoe Chi
(1979) - Paquot, C. (1979a). Determination of the acid value (AV). In Standard methods for the analysis of oils, fats and...
Cited by (46)
Fate of microplastics during composting and their leachability
2022, Sustainable Chemistry and PharmacyCitation Excerpt :BHT concentration was lowered by the breakdown of BHT to its degradation products, e.g., BHT-CHO (3,5-di-tert-butyl-4-hydroxybenzaldehyde). BHT-CHO is formed by the oxidation of the alkyl substituents of BHT to p-methyl group (Nieva-Echevarría et al., 2015); this process was described to occur between 70 and 140 °C (Zhang et al., 2004). BHT-CHO was identified in the dry matter of compost in the range from 1.80 mg/kg (six months) to 16.20 mg/kg (input raw material).
Antioxidant properties of two novel lipophilic derivatives of hydroxytyrosol
2020, Food ChemistryCitation Excerpt :BuMT and BuHT both provided a much stronger protective effect than TBHQ at higher temperature experiments (>110 °C) such as Rancimat and deep frying, however at lower temperatures (<65 °C) their protective effect seems to diminish. In addition, the superior antioxidant activity demonstrated by TBHQ in comparison with HT and its new lipophilic derivatives, especially BuMT, at lower temperature in this work is also evident in the studies done by Zhang et al. (2004). This observation was as a result of the two para-hydroxyl groups on TBHQ which can release hydrogen atoms to active peroxyl radicals in edible oils to interrupt the oxidative chain reaction (Nissiotis & Tasioula-Margari, 2002).
Screening of antioxidant additives for biodiesel fuels
2018, Renewable and Sustainable Energy ReviewsCitation Excerpt :Toxicity of antioxidants is also one of the prime considerations while selecting antioxidants for biodiesel fuels. Generally, hindered phenol antioxidants such as BHT, BHA and TBHQ are colorless, odorless, cheap and less-toxic [39]. On the other hand most aromatic amine antioxidants are toxic in nature and some of them are carcinogens [134].
Climate Changes and Potential Impacts on Quality of Fruit and Vegetable Crops
2014, Emerging Technologies and Management of Crop Stress Tolerance: Biological TechniquesTechno-functional attributes of frying additives
2023, Frying Technology: Recent Development, Challenges, and Prospects