Microencapsulation Attenuates Nitrite Accumulation and Modulates Nitrate Availability in Spinach Juice during Storage

High Resolution Image Download MS PowerPoint Slide Dietary nitrate-rich vegetables are increasingly used in functional foods. However, the stability of nitrate, nitrite, and antioxidants during storage remains a major challenge. The present study investigated the effects of microencapsulation on nitrate-nitrite dynamics and antioxidant stability in spinach juice during 30 days of storage at 25 °C, 4 °C, and −20 °C, compared with a nonmicroencapsulated matrix. Microencapsulation was performed by spray drying using maltodextrin. In nonmicroencapsulated juice, nitrate showed an initial decrease followed by a progressive increase, while nitrite exhibited significant temperature-dependent accumulation, particularly at 25 °C. Antioxidant concentration and capacity significantly declined in nonmicroencapsulated juice under ambient conditions. In contrast, microencapsulated spinach juice exhibited stable nitrite levels, preserved antioxidants, and increased nitrate concentration through enhanced release from the microencapsulated matrix. These findings suggest that microencapsulation modulates nitrate availability and improves the stability of nitrate-rich vegetable matrices, representing a promising strategy for the development of shelf-stable functional food products.