Production and characterization of Solar Sea salt in La Union, Philippines

The Philippine salt industry has declined due to various factors such as climate change, age-old laborious production methods, and changes in livelihood preferences. To jumpstart the revival of the salt industry in the province of La Union, a small-scale salt production process for coastal communities was developed using solar evaporation of seawater on the HDPE platform. The quality of seawater and the produced solar sea salt were determined based on physicochemical analysis, microbial and heavy metal contamination tests and salt yield. The study used four treatments based on the volume of seawater poured into the HDPE platform: T1, 100 li; T2, 200 li; T3, 300 li; T4, 400 li. The study was conducted in a Randomized Complete Block Design. Data were analyzed with ANOVA and Duncan Multiple Test for further test of significance using SPSS version 23. The salinity of seawater, taken at a depth of 0.59 meters, was 35-37 ppt, the water temperature was 29.1 - 31.54 ⁰C, and the pH was 8.21 - 8.03. The solar drying to produce sea salt took 7-19 days, depending on seawater quantity, and the highest yield was attained in T3 with three monthly production cycles. The NaCl content of produced sea salt ranged from 81.93±0.87 - 82.57±0.20 %, and Iodine (I) content of 46.03±0.94 - 48.16±1.96 mg/kg. Inorganic arsenic (i-As) was in a range of 0.075±0.75- 76.81±1.91 μg/g, and lead (Pb) content from 9.07±0.71 - 9.41±0.48 mg/kg. Salmonella was not detected, while E. coli, and S. aureus were within the microbiological limits for the food-grade product.