Fermentation of yellow carrot juice (Daucus carota L.)‎ via probiotic lactic acid bacteria during storage

الملخص EN

There is a great demand for the vegetarian probiotic products, as an alternative to fermented dairy products.

Probiotication may improve flavour, taste and extends the shelf-life of vegetarian juices with great regards to its high nutritional value.

Therefore, the aim of this study was to evaluate the effect of using probiotic Lactic Acid Bacteria (LAB) namely, (Lactobacillus plantarum ssp.

plantarum EMCC ١٠٢٧, Lactobacillus delbrueckii ssp.bulgaricus EMCC ١١٠٢) and their mixture for the fermentation of carrot juice during cold storage (٤±١oC) for ١٢ days.

Fresh carrot juice was inculcated with selected LAB (approximately ٥-٦×١٠٩ CFU/ml of juice).The juice was initially fermented at ٣٧°C for ٣ days.

Bacteria survival in intervals at ٣, ٦, ٩, and ١٢ days were counted.

The number of LAB bacteria after ١٢ days of cold storage (٤±١oC) was more than ٦.٥×١٠٨ CFU/ml of juice.

After ٣ days of fermentation, the pH values was decreased from ٥.٧ to ٤.٢, while, the acidity (%) was increased from ٠.١٥ % (as lactic acid) to ٠.٦٥%, the number of L.

bulgaricus was higher than L.

plantarum, or mixed culture (١:١) in consumption of reducing sugars, ٢.١١, ٢.٤٥, and ٢.٥١, after ٣ days, and ١.٤٥, ١.٩٧, and ١.٧٧ g/١٠٠ ml, after ١٢ days of cold storage, respectively.

The viable cell counts of L.

plantarum decreased slightly during cold storage, but the cell viability remained at a considerably high level (>١٠٦ CFU/ml) after ١٢ days of cold storage (٤±١oC).TSS (%) decreased from ٧.٨٠ to ٦.٩٠ in the fermented sample with mixed culture (١:١), L.

bulgaricus, was ٧.٨٠ to ٦.٩٠, and L.

plantarum decreased from ٧.٨ to ٧.١٠, from initial time to ١٢ days of storage, respectively.

(ΔE) values were highest for the sample with mixed culture =٧٣.٨, L.

plantarum =٧٢.٢, and L.

bulgaricus =٧٣.٥, after ١٢ days of cold storage.

This suggests that fermented carrot juice, which containing LAB, could serve as a healthy beverage for vegetarians and lactose-allergic consumers.