Abstract
The repeated use of cooking oils and ghee for the deep frying of food materials may affect their nutritional quality. The present study evaluated the effect of repeated frying on the ...physicochemical characteristics and antiradical potential of canola oil and ghee. The oil and ghee were used for frying of fish and chicken for 2, 4, 6, 8, and 10 frying cycles followed by the analysis of physicochemical, oxidative stress, and antiradical parameters. Regression analysis of the data showed a frying cycle‐dependent significant linear increase in saponification (
R
2
= 0.9507–0.9748), peroxide and acid values (
R
2
= 0.956–0.9915), and malondialdehyde (MDA) production (
R
2
= 0.9058–0.9557) of canola oil and ghee subjected to fish and chicken frying but exponential increase in saponification value (
R
2
= 0.9778) and MDA production (
R
2
= 0.7407) of canola oil and ghee used for fish frying. The increase in the number of frying cycles linearly decreased the iodine value (
R
2
= 0.9781–0.9924), and 1, 1‐diphenyl‐2‐picrylhydrazyl, hydroxyl, and 2, 2′‐azino‐bis(3‐ethylbenzthiazoline‐6‐sulfonic acid) radical scavenging potential (
R
2
= 0.9089–0.9979) of canola oil and ghee. Repeated frying in cooking oil and ghee increases oxidative stress and decreases their physicochemical and antioxidant qualities. Canola oil was comparatively more oxidative resistant than canola ghee. The regression equations derived from regression analysis will guide researchers to conduct similar types of univariate studies.
Fifty traditional Tibetan ghee (TTG) varieties were collected and analyzed their systematic characteristic indices, including physicochemical parameters, minerals, fatty acid composition, and thermal ...behavior. Results show that TTG contains a large amount of fat (71.68%–93.3%) and a small quantity of protein (0.51%–1.81%). The acid and peroxide values of TTG vary from 0.02 to 1.30 mg/g and 0.07 to 5.93 meq/kg, respectively. The content of minerals varied with altitude level and region significantly (p < 0.05), and the regional variations of fatty acids in TTG were also observed significantly, these differences may be due to the high unsaturated fatty acids level in the cow diets.
Summary
Ghee residue (clarified butter sediment waste) is a fat‐rich by‐product (containing 50–70% fat, weight basis) obtained during ghee (clarified butter fat) preparation. Conventionally used fat ...extraction methods from ghee residue (GR) are energy intensive and generates huge amount of waste water. In the present study, solvent extraction was explored for milk fat separation from GR at different extraction temperatures using green solvents, viz., ethyl acetate (EA) and di‐methyl carbonate (DMC). Changes in differential scanning calorimetry profile, fatty acid profile, dynamic rheology, FTIR spectroscopy and colour values of the solvent extracted fat were studied. Increasing the solvent extraction temperature increased the fat extraction efficacy from 45.62% to 49.22% for DMC and from 48.70% to 52.16% for EA. Considering the fat extraction efficacy, fat extraction from GR was found suitable using EA at 65°C extraction temperature. Fat extraction from GR using the selected green solvent, that is EA needed only 57% (18 000 J g−1 of GR) of energy as compared to conventional method (31 500 J g−1 of GR) with no wastewater generation.
Solvent extraction using green solvents were explored for fat extraction from GR. EA and DMC were used for fat extraction from GR at different extraction temperature. Increasing extraction temperature increased the fat extraction efficacy. Solvent extraction was economical than conventional method of fat extraction from GR.
Process parameters were optimised using Taguchi orthogonal array design for extraction of phospholipids (PLs) from ghee residue (GR) with pulsed electric field (PEF) assistance. For higher PL yield ...and antioxidant activity, process voltage and time were observed to be significant factors. Optimised conditions were determined as 60 kV/cm voltage at 7.5 (v/w) solvent (water)‐to‐solid ratio for 5 min. Physical disruption of GR matrix due to PEF treatment was established through scanning electron micrographs. Lipidomic profile of the extract ascertained through liquid chromatography‐mass spectrophotometry (LC–MS) revealed multiple species of phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and phosphatidylserine in the resultant extract.
Due to the lack of basic information on Chinese ghee and the increasing demand of consumers for natural oils, this study aims to explore and distinguish the quality characteristics of ghee in ...different regions of China. Ghee samples from 16 regions of Qinghai Province, Gansu Province, Xinjiang Uyghur Autonomous Region, and Tibet Autonomous Region were selected and their physicochemical properties, fatty acids, texture, antioxidant and antibacterial activities were determined. The results showed that: (1) The physicochemical properties of ghee were different from different regions, but the freshness and fat content are generally high. The results of iodine value and saponification value suggest that the fatty acid composition is good; (2) The unsaturated fatty acid/saturated fatty acid content of ghee in Tibet and Xinjiang ranges from 63.05% to 79.13%, which is better than that in other regions; (3) Gansu Diebu ghee has the highest hardness (40.69 N); (4) Ghee from different regions has good antioxidant activity, DPPH free radical scavenging activity is 30.45% to 58.06%, ABTS free radical scavenging activity is 41.14% to 65.53%, and has varying degrees of inhibition on gram-positive bacteria. In addition, yak ghee, cattle-yak ghee and cow ghee have better fatty acid composition and antibacterial ability than scalper ghee. The results of this study distinguish the differences in the quality characteristics of yak ghee in different geographical regions. Therefore, it can provide a theoretical basis for the origin tracing and quality-oriented improvement of yak ghee.
Raman spectroscopy as a fast and nondestructive technique has been used to investigate heating effects on Desi ghee during frying/cooking of food for the first time. A temperature in the range of ...140–180℃ has been investigated within which Desi ghee can be used safely for cooking/frying without much alteration of its natural molecular composition. In addition, heating effects in case of reuse, heating for different times, and cooking inside pressure cookers are also presented. An excitation laser at 785 nm has been used to obtain Raman spectra and the range of 540–1800 cm−1 is found to contain prominent spectral bands. Prominent variations have been observed in the Raman bands of 560–770 cm−1, 790–1160 cm−1, and 1180–1285 cm−1 with the rise in temperature. The spectral variations have been verified using classifier principal component analysis. It has been found that Desi ghee can be reused if heated below 180℃ and it can be heated up to 30 min without any appreciable molecular changes if a controlled heating can be managed.
Ghee is a premium product in Southeast Asia and is prone to adulteration with vegetable oils/ fats. The main aim of the study was to develop an easy-to-use paper-based sensor to detect this ...adulteration. Hence, a protocol involving hexane and acetonitrile for the extraction of synthetic antioxidants from adulterated ghee and its rapid detection using DPPH was standardized. Paper-based discs impregnated with 4 mM DPPH were developed. The developed paper-based disc sensors worked well and their response time was indirectly proportional to the antioxidant concentration (0.0025–0.02%). Using the developed disc sensors, the palm oil, and sunflower oil added to cow ghee @2.5% or more, and 1% or more, respectively could be detected. The shelf life of the developed sensors was 30 and 90 days at 30 °C and 4–6 °C, respectively. In stored cow ghee samples, the response time of the sensors increased as the storage period of ghee samples increased. The cutoff limit to declare the sample of cow ghee as unadulterated was fixed to 60 min. Based on the response time of the sensor, the level of detection of vegetable oils in stored cow ghee was found to be 2.5%.
PDF
