Original article Polyphenolic and phytochemical content of Cucumis sativus seeds and study on mechanism of preservation of nutritional and quality outcomes in enriched mayonnaise Packirisamy Azhagu Saravana Babu, 1 Basheer Vajiha Aafrin, 1 Ganesan Archana, 1 Kalleary Sabina, 1 Kasirajan Sudharsan, 1 Kesavan Radha Krishnan, 2 Srinivasan Babuskin, 3 Meenatchisundaram Sivarajan 4 & Muthusamy Sukumar 1 * 1 Centre for Food Technology, A.C.Tech, Anna University, Chennai, India 2 Department of Food Processing Technology, CIT, Kokrajhar, India 3 JCT College of Engineering & Technology, Coimbatore, India 4 Central Leather Research Institute, Chennai, India (Received 24 January 2016; Accepted in revised form 6 March 2016) Summary Oxidative rancidity in food emulsions leads to a reduction in shelf life. Synthetic antioxidants are widely used in food industry to prevent the development of rancidity. The present study was focussed on investigating the antioxidant potential of Cucumis sativus seeds (CSS) and correlates these findings with mayonnaise enrichment and extends its shelf life. CSS exhibited the highest abundance in phenolic compounds (93.5 Æ 0.1 mgGAE g À1 ), flavonoids (57.4 Æ 0.1 mgQE g À1 ), b-carotene (19.46 Æ 0.4 mg carotenoids per 100 g) and high free radi- cal scavenging activity. CSS (200 ppm) and butylated hydroxyanisole (200 ppm) were incorporated in mayon- naise and the oxidative stability was evaluated by peroxide, p-anisidine and TBARS values during storage at different temperatures. Organoleptic evaluations indicated that CSS enriched sample was recorded the highest overall acceptability. The results from our study will provide scientific basis for CSS as natural preservative against lipid oxidation or food enrichment while developing functional foods. Keywords Antioxidants, Cucumis sativus, mayonnaise, polyphenols, shelf life. Introduction Utilisation of plant extracts as an alternative to syn- thetic antioxidants and antimicrobials to combat the foodborne pathogens, inhibiting lipid oxidation and thus extending the shelf life, is an increasing trend in the food industry (Farhadi et al., 2016). Polyphenols have received increased attention due to their remark- able health benefits on various oxidative stresses asso- ciated diseases, such as cancer, cellular ageing and cardiovascular diseases (Samec et al., 2016). According to the World Health Organization (WHO, 2002), medicinal plants would be the best source to obtain a variety of bioactive compounds. Therefore, such plants should be investigated to better understand their prop- erties, safety and efficiency (Akeel et al., 2014). The incorporation of natural antioxidants, which are mole- cules capable of preventing or delaying the oxidative lipid damage represents a key alternative to overcome the quality deterioration of lipid-based food products, provoked mainly by the attack of the reactive oxygen species (ROS) (Aleman et al., 2015). Natural antioxi- dants can act as retarders, when they counteract lipid oxidation by protecting target lipids from oxidation initiators or by hindering the propagation phase, the so-called chain-breaking antioxidants (Ahmad et al., 2016; Yang et al., 2016). Recent years, food enrich- ment seems to be an easy and cheap way for improv- ing nutritional quality. The global demand for new sources of functional food has been focused mostly on plants (Velasco & Beltr an, 2016). Cucumis sativus seeds (CSS) are being utilised poorly, it could be used as the best candidate for producing high-quality functional food, and its polyphenols are playing a big role in the inhibition of lipid oxidation by neutralising free radi- cals, quenching singlet and triplet oxygen, or decom- posing peroxides and are able to modulate the sensitiveness to lipid oxidation (Kumar et al., 2010; Ye et al., 2015). Incorporation of antioxidants in lipid- containing foods is one method to minimise rancidity and retard the formation of toxic oxidation products *Correspondent: E-mail: sukumarcbt@gmail.com International Journal of Food Science and Technology 2016, 51, 1417–1424 doi:10.1111/ijfs.13109 © 2016 Institute of Food Science and Technology 1417