Effect of Pre-Treatment on Bitterness and Quality of Osmodehydrated Lemons

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Lemons are rich in beneficial phytochemicals and antioxidants, including phenolic compounds and flavonoids. However, some of these compounds impart a bitterness that can limit its application in food products and affect consumer acceptance. This study aimed to reduce the bitterness of osmodehydrated lemon using a combination of pre-treatment, osmotic dehydration, and drying processes. Fresh lemons, lemons immersed in 2 % NaCl for 3 nights, and lemons stored at room temperature for 3 days were analyzed for bitter compounds. These samples underwent 4 cycles of blanching at either 35 or 80 °C, followed by cooling, osmotic dehydration in a 60 °Brix sugar solution with heating at 80 °C for 45 min and soaking in syrup for an additional 30 min, and finally drying at 70 °C until reaching a water activity below 0.6. Results indicated that the optimal condition for reducing bitterness involved storing fresh lemons at room temperature for 3 days, soaking them in 2 % NaCl solution for 3 nights, and blanching at 80 °C, followed by osmotic dehydration and drying. The naringin, limonin, and hesperidin contents were reduced by 34-fold, 24-fold, and 10-fold, respectively, compared to those in fresh lemons. Additionally, its sensory properties were well accepted by panelists. Although the production cost at the laboratory scale was high, it is expected to be lower at pilot or commercial scales. The production method is deemed suitable for entrepreneurial ventures in the lemons processing industry. HIGHLIGHTS Value Addition: The study explored effective methods to value added and utilize lemon fruits by employing pre-treatment, blanching and cooling cycles, osmotic dehydration, and drying. Bitterness Reduction: The optimized production process significantly reduced the bitterness of the osmodehydrated lemon product. High Quality Process: The optimized production process resulted in high-quality osmodehydrated lemon products. Pre-Processing Storage: Storing fresh lemons at room temperature for 3 days before processing was effective in reducing bitterness. Consumer Approval: Panelists rated the osmodehydrated lemon favorably, indicating strong consumer preference. GRAPHICAL ABSTRACT