Whatman s filter paper no 41

All subjects underwent a detailed ophthalmological examination, including Schirmer test, tear break up time (TBUT) test and ocular surface staining (OSS). Schirmer test is a standard measure of aqueous tear production and is safe, easy to perform and inexpensive. Whatman’s filter paper (No. 41) of 5 x 35 mm length was placed in the outer 1/3 portion of both lower eyelid fornices and the length of wetting was measured and ≤ 5 mm at the end of 5 minutes was defined as definitely decreased tear production. TBUT is an indicator of tear film stability and commonly used in the assessment of dry eye disease. Sodium fluorescein is installed into the lower conjunctiva and the patient is asked to look straight ahead and blink a few times. The tear film is observed under blue light and the time between the last blink and the first dry spot is recorded. More than 10 seconds is considered normal, 5 to 10 seconds marginal and < 5 seconds was considered as abnormal TBUT. According to the Oxford Scale, the OSS was graded between stage 0 and 5 and then categorised as mild (stage 0-1), moderate (stage 2 or 3), or severe (stage 4-5).

In the laboratory, rice samples were cooked in aluminium vessels (popularly called Handi) on an electric heater following the traditional cooking method having the rice-to-water ratio of 1:3 and the gruel was discarded. Similar to the farmer's family, to prepare SCR, after cooling the cooked rice, CR samples were soaked in three times of ground/tap water (As free) added into it and kept at room temperature. While preparing SCR the pH of the soaking medium was noted at the beginning of the process and after 12 h of soaking. First the soaking medium i.e. water of soaked cooked rice separated using a strainer followed by Whatman's No.41 filter-paper. Then the pH of the filtrate of the SCR soaking medium was determined using Oakton® pH 150 Waterproof Portable pH/mV/Temperature Meter in triplicates (Table S2).