The Effect of Fermentation on the Physicochemical Characteristics of Dry-Salted Vegetables

Serap Vatansever,Clifford A Hall Iii,Anuradha Vegi,Julie Garden-Robinson

doi:10.5539/jfr.v6n5p32

Abstract

The local food movement has prompted interest in fermented vegetables, especially novel combinations of vegetables. The physicochemical characteristics of dry-salted (2% Sodium Chloride [NaCl]) fermented carrots, daikon radish, red cabbage, carrot + daikon radish (mix I), and red cabbage + daikon radish (mix II) were examined during a 14-day fermentation at room temperature. The fermentation process was monitored through the measurement of pH, titratable acidity, and Brixvalue. Further, effects of fermentation on shredded vegetables were determined by measuring color, water activity, and texture (hardness). During the fermentation process, pH of fermented carrot, daikon radish, red cabbage, and mix I and mix II decreased significantly (p < 0.05) to 3.99±0.04, 4.17±0.05, 3.76±0.11, 3.74±0.18, and 3.70±0.05, respectively, at the end of fermentation (10 days for carrot and 14 days for other vegetables). Titratable acidity (% as lactic acid) in fermented carrot, daikon radish, red cabbage, and mix I and mix II increased throughout fermentation, and final fermentation day acidity values were 1.39±0.12, 0.78±0.02, 1.54±0.09, 1.2±0.06, and 1.50±0.07%, respectively. In general, fermentation did not impact significantly color, water activity, hardness values of fermented vegetables. The use of the dry-salting method has applications in other vegetables besides cabbage. The study results support the use of this method for other vegetables and also might be useful to provide knowledge helpful in the local food movement.

Highlights

Fermentation has been used as a simple, economical, and effective food preservation process since ancient times (Joshi & Sharma, 2009; Kabak & Dobson, 2011; Hunaefi, Akumo, & Smetanska, 2013)
Titratable acidity (% as lactic acid) in fermented carrot, daikon radish, red cabbage, and mix I and mix II increased throughout fermentation, and final fermentation day acidity values were 1.39±0.12, 0.78±0.02, 1.54±0.09, 1.2±0.06, and 1.50±0.07%, respectively
Red cabbage was cut into 2 mm thick strips (Hunaefi et al, 2013), while peeled carrot and daikon radish were shredded (Joshi & Sharma, 2009)

Summary

Introduction

Fermentation has been used as a simple, economical, and effective food preservation process since ancient times (Joshi & Sharma, 2009; Kabak & Dobson, 2011; Hunaefi, Akumo, & Smetanska, 2013). Some significant advantages of fermentation include: (1) increasing acidity and pH reduction with the production of organic acids, such as lactic acid by lactic acid bacteria (LAB) and (2) enhancing nutrition, organoleptic, and shelf life properties of foods through by-product (e.g. lactic acids, acetic acids and other volatiles) formation (Joshi & Sharma, 2009; Hunaefi et al, 2013), and synthesizing essential amino acids and many vitamins (Kabak & Dobson, 2011) by either useful bacteria, such as LAB or beneficial yeasts, or both (Food and Agriculture Organization [FAO], 1998). Fermented dairy and meat products are more commonly produced and consumed when compared to fermented vegetables, and they have a better commercial market than fermented vegetables (Cetin, 2011). Fermented vegetables will have better marketability in the local food movement as alternative nutritional sources

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