Optimization of Thermal Processing for Crystallization Control and Quality Retention in Mustard Honey

Abstract

Mustard honey crystallises rapidly during storage because of its sugar composition, which can reduce consumer acceptability and complicate post-bottling handling. This study evaluated the effect of controlled thermal processing on crystallisation behaviour and selected physicochemical quality attributes of mustard honey. Fresh honey samples were thermally treated at 50, 60, and 70 °C for 15, 45, and 75 min. The evaluated parameters included moisture content, total soluble solids, total sugars, reducing sugars, glucose, fructose, sucrose, hydroxymethylfurfural content, diastase activity, total phenolic content, colour, firmness, consistency, and index of viscosity. Storage behaviour was further assessed for selected samples treated for 15 and 75 min over a 90-day period. Fresh mustard honey had 82.00 °B total soluble solids, 17.61% moisture, 81.78% total sugar, 76.80% reducing sugar, 37.17% glucose, 39.63% fructose, 4.98% sucrose, 9.87 mg/kg hydroxymethylfurfural, and a diastase number of 14.50. Thermal treatment caused gradual reductions in glucose, fructose, diastase activity, total phenolic content, firmness, consistency, and index of viscosity, while hydroxymethylfurfural increased with higher temperature and longer heating time. All hydroxymethylfurfural and diastase values remained within the reported regulatory limits. During storage, untreated honey showed early crystallisation, whereas treatment at 70 °C effectively delayed firmness and consistency development. Heating at 70 °C for 15 min provided effective crystallisation control over 90 days while limiting excessive thermal exposure. The results indicate that short-duration thermal treatment can help maintain the flow properties and physicochemical quality of mustard honey during storage.