To assess the validity of QuickView to estimate retinyl palmitate and to classify coconut oil as adequately fortified.
The QuickView Vitamin A Test Kit estimates vitamin A content in oil from 5-25 mg RE/kg (in increments of five) based on the Carr-Price reaction. High Performance Liquid Chromatography (HPLC) was the reference method. Linearity and agreement was described. Combinations of QuickView concentrations were used to predict the fortification status and minimum thresholds. A sample size of 100 allowed for the estimation of a specificity of 85%. Fortification status was based on Philippine implementing rules and regulations (IRR) : 1) IRR (12 23 mg RE/kg) and 2) IRR20 (9.6 27.6).
Linearity was defined by y=0.9317 + 5.04x ; R2 is 0.66. The mean difference was -4.036 mg RE/kg. The observed agreement was 64% (IRR) and 92% (IRR20) with kappa(IRR) = 0.22 (p<0.01) and kappa(IRR20) = 0.67 (p < 0.0001).The sensitivity and specificity were 86% and 85% with QV 7 (10 - 20 mg RE/kg) and 95% and 71% with QV 6 (10-15 mg RE/kg) against IRR20. Against IRR, specificity was above 90% if sensitivity was 60%. QuickView performs best (80-100% sensitivity and specificity) when used to identify a minimum threshold of 10 or 15 mg RE/kg without taking into account a ceiling level.
The kit is best used to estimate minimum thresholds of vitamin A content in fortified coconut cooking oil.