2.7.2. Analytical procedures
Moisture content, refractive index, iodine value (IV), and saponification value of oil samples were measured according to the AOCS Ca 2d-25, Cc 7-25, Cd 1d-92, and Cd 3-25 methods, respectively. Measurement of Peroxide value (PV), free fatty acid (FFA), and p-anisidine value (P-AV) were made after a regular interval of 15 days, following the AOCS official methods (AOCS, 2003). Total carotenoid and chlorophyll content were determined according to Jabri-Karoui & Marzouk (2014) using a UV–Vis spectrophotometer (Pharmacia Biotech Ltd., Cambridge, UK) at 470 and 670 nm, respectively, using the following equations:
\(\text{Total\ chlorophyls\ }\left(\frac{\text{mg}}{\text{kg}_{\text{oil}}}\right)=\ \frac{A_{470\ nm}\ \times\ 10^{6}}{613\ \times 100\ \times d}\)(2)
\(\text{Total\ carotenoids\ }\left(\frac{\text{mg}}{\text{kg}_{\text{oil}}}\right)=\ \frac{A_{670\ nm}\ \times\ 10^{6}}{2000\ \times 100\ \times d}\)(3)
Where A is the maximum absorption in given wavelength, d is the thickness of the cuvette = 1 cm, 613 and 2000 is the coefficient of specific extinction in cyclohexane of pheophytin and lutein, respectively. Temperature and relative humidity of oil samples storage was 25 ℃ ± 5 and 30–35%., respectively.
The protein, fat, moisture, ash, crude fibre and total titrable acidity values of Senjed fruit were estimated using standard methods of analysis (AOAC, 1990). Total soluble sugar (%) content was determined according to Cansev et al. (2011).