Comparative Investigation of Quality Features and Microbiological Safety of the Spicy “Ndjindja” (Zingiber officinale) Drink Made From Various Production Sites in Far North of Cameroon

Abstract

“Ndjindja” is a spicy drink made by the processing of Zingiber officinale roots using techniques varying from one location to another. To investigate the effect of production site on the quality features and safety of “ndjindja,” the producers were surveyed and the samples from seven production areas (Bogo, Gazawa, Koza, Maroua, Mokolo, Mora, and Tokombéré) in the Far North of Cameroon were subjected to standard analysis methods to compare the physicochemical, phytochemical, sensory, and microbiological parameters. Sorting, washing, cutting, crushing, squeezing, adding water and sugar, and packaging are all required in the production of “ndjindja.” However, peeling and adding lemon, aroma, and sweeteners (additives), as well as pasteurization, included some optional steps. The pH (3.7–4.8), titratable acidity (0.60%–1.3%), electrical conductivity (7.0–12 × 10² µS/cm), and contents of soluble solids (2.0–9.3°Brix), dissolved solids (3.5–6.1 × 10² ppm), dry matter (1.4%–7.7%), ash (0.30%–1.1%), soluble protein (0.80–3.4 mgBSAE/mL), and free amino acid (0.42–1.5 mgAE/mL) varied significantly (p < 0.05) across the production sites. The “ndjindja” from the Koza site recorded the largest mean contents of dietary fibers, polyphenols, flavonoids, and tannins (4.7%, 54 mgPGE/100 mL, 14 mgQE/100 mL, and 19 mgCE/100 mL, respectively), as well as the greatest relative antioxidant capacity index (RACI = 1.4) and overall acceptability (7.5). Microbiological analysis revealed the presence of spore-forming bacteria, fungi, Coliforms, Streptococci, and Staphylococci in the “ndjindja.” However, the beverage from the production sites of Maroua and Mokolo had the lowest safety scores (2.7), indicating the best microbial safety status. Given all the above, “ndjindja” produced in the Koza site may be regarded for bioactive and functional considerations, whereas the one produced in the Maroua and Mokolo sites should be promoted regarding its microbial safety status.