A simple and highly sensitive spectrophotometric method was developed for the determination of thiobarbituric acid reactive substances (TBARS) as a marker for lipid peroxidation in fried fast foods. The method uses the reaction of malondialdehyde (MDA) and TBA in the glacial acetic acid medium. The method was precise, sensitive, and highly reproducible for quantitative determination of TBARS. The precision of extractions and analytical procedure was very high as compared to the reported methods. The method was used to determine the TBARS contents in the fried fast foods such as Shami kebab, samosa, fried bread, and potato chips. Shami kebab, samosa, and potato chips have higher amount of TBARS in glacial acetic acid-water extraction system than their corresponding pure glacial acetic acid and vice versa in fried bread samples. The method can successfully be used for the determination of TBARS in other food matrices, especially in quality control of food industries.

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Adiantum capillus-veneris is important endangered fern species with several medicinal properties. In this study, the leaves samples were extracted and separated using reversed phase HPLC with DAD for carotenoids, chlorophylls and phenolic compounds. Separation of carotenoids and chlorophylls were carried out using a tertiary gradient system of water, MTBE and methanol-water, while a binary gradient system of methanol-water-acetic acid was used for phenolic profiling. Results revealed eight carotenoids, four pheophytins, and two chlorophylls. Lutein (806.0 μg/g), chlorophyll b′ (410.0 μg/g), chlorophyll a (162.4 μg/g), 9′-Z-neoxanthin (142.8 μg/g) and all-E-violaxanthin (82.2 μg/g) were present in higher amounts. The relatively high amounts of lutein may be one of the key indicator of beneficial antioxidant properties. The phenolic profile revealed a total of 13 compounds, namely 4-hydroxybenzoic acid, chlorogenic acid, caftaric acid, kaempferol glycosides, p-coumaric acid, rosmarinic acid, 5-caffeoylquinic acid, and quercetin glycosides. Kaempferol-3-sophorotrioside (58.7 mg/g), chlorogenic acid (28.5 mg/g), 5-O-caffeoylquinic acid (18.7 mg/g), coumaric acid (11.2 mg/g), and its derivative (33.1 mg/g) were present in high amounts. These results suggest that the reversed phase HPLC profiling of Adiantum leaves provides a better understanding in to the actual composition of bioactive compounds, which may be responsible for the potential medicinal properties. Adiantum leaves rich in important bioactive phytochemicals can be used as a possible source of nutraceuticals or as a functional food ingredient.

Spinach extract is added to sunflower oil in different ratios to assess its suitability during thermal stress. The fortified sunflower oils are thermally oxidized along with their control. Fortified sunflower oils are characterized for peroxide (PV), p‐anisidine (AV), thiobarbituric acid (TBARS), total phenolic contents, and radical scavenging activity (RSA). Polyphenols in the oil samples are extracted and identified using reversed phase high‐performance liquid chromatography with a diode array detection system (HPLC‐DAD). Results reveal separation and identification of 14 and 22 polyphenolic compounds in control and fortified oil samples, respectively. The major phenolic compounds are p‐hydroxybenzoic acid (1.99–11.3 μg g−1), p‐coumaric acid (0.22–10.2 μg g−1), isorhamnetin‐3‐(hydroxyferuloyl‐glucoside)‐7‐glucoside (0.14–13.8 μg g−1), apigenin (0.15–13.2 μg g−1), kaempferol‐3‐(p‐coumaroyl‐diglucoside)‐7‐glucoside (3.88–19.8 μg g−1), apigenin‐2‐O‐pentoxide‐8‐hexoside (0.42–39.7 μg g−1), quercetin‐3‐(sinapoyl‐diglucoside)‐7‐glucoside (1.99–11.3 μg g−1), and kaempferol‐3‐(sinapoyl‐diglucoside)‐7‐glucoside (1.73–34.6 μg g−1). Significant variations are observed in the composition of these phenolic compounds during heating. Remarkable beneficial changes are also observed in the characteristics of the oils such as peroxide, anisidine, and TOTOX values during thermal treatment. In conclusion, spinach leaf extracts are protective and beneficial for thermal stability of sunflower oil. Practical Applications: Thermal stability of frying oil is an important topic in food science and technology. The low stability of frying oils can be enhanced with the addition of natural antioxidants. Food industries may use antioxidants from plant leaves extract, especially spinach leaf, extracts to be very beneficial. The phenolic profile, lipid oxidation, and antioxidant activity of sunflower oil fortified with spinach leave extracts are enhanced. These results suggest that spinach leaves extract is beneficial in terms of lipid oxidation parameters and serve as a good source of important phenolic compounds. Spinach extract added to sunflower oil is beneficial during thermal stress. Significant variations are observed in the composition of different phenolic compounds during heating. Spinach extract contributes beneficial changes to the quality characteristics of the oils such as peroxide, anisidine, and TOTOX values.