BIOCHEMICAL VARIABILITY OF VEGETABLE JUICE POWDERS: A KEY FACTOR IN MODULATING THE PHYSICOCHEMICAL PROPERTIES AND SAFETY PROFILE OF VEGAN FERMENTED SAUSAGES

Abstract

This research focuses on developing Thai mushroom vegan sausages (Naem Het) with improved quality and safety profiles by incorporating pumpkin seed protein isolate (PSMPI) and vegetable juice powders (yellow beet, celeriac, yellow carrot, radish) as functional ingredients. Their effects on sensory and microbiological parameters, nutritional value, and stability were evaluated. The growing demand for plant-based meat analogues necessitates the development of high-quality fermented products. A key challenge remains the achievement of desirable characteristics without synthetic additives; therefore, the use of vegetable juices as natural nitrite precursors in mushroom-based systems is a promising but under-researched area. Five formulations (A0 and 4 experimental ones) were analyzed for their chemical composition, microbiological parameters (aerobic mesophilic bacteria, lactic acid bacteria, coliforms, pH, NO3–/NO2–), and sensory properties during fermentation and 14 days of storage. It was found that PSMPI significantly increased the protein content (from 8.50% in A0 to 10.75% in A1) and improved the texture. The vegetable powders effectively served as sources of NO3–, modulating microbial activity. Based on a comprehensive evaluation, the samples with beetroot (A1) and carrot (A3) were identified as the best. They exhibited superior sensory profiles compared to the control A0 (7.87), receiving the highest overall scores on a 9-point scale – 8.22 (A1) and 8.12 (A3) – and demonstrated optimal microbiological stability (pH 4.49–4.51, LAB ≈ 8.3–8.5 log10 CFU/g). This comprehensive positive effect was attributed to the high content of pigments with antioxidant properties in these vegetables, which facilitated a controlled fermentation. In contrast, in the samples with celery and radish, a significantly lower pigment content impaired the bacterial reduction of their extremely high initial NO3 – content (270–290 mg/kg), leading to a unique dynamic and maximal ac-cumulation of NO2–. Thus, this research confirms that the judicious selection of vegetable juice powder is an effective tool for creating high-quality, safe, and sensorially appealing vegan fermented products.