Comparative examination of activity of different strains of lactic acid bacteria in beetroot and carrot juice

Abstract

Fermented vegetable juices are an important component of nutrition, because the fer­mentation improves the quality of natural vegetable juices by its products, which are impor­tant biotic substances. Beetroot (Beta vulgaris L.) and carrot (Daucus carota L.) are vegetables that can be preserved by biological fermentation. The aim of this research was comparative examination of activity of Lb. plantarum A112 and natural isolates Lb. acidophilus BGSJ15-3 in lactic-acid fermentation of beetroot and carrot juice. Activity of these strains was expressed as the number of viable cells, pH value, lactic acid and sugar content. The results of this work showed that beetroot and carrot juices are good substrates for growth and fermentative activity of investigated strain of lactic acid bacteria. According to content of lactic acid in fermented juices and to decreasing of glucose content, it may be concluded that strain Lb. acidophilus has better activity than Lb. plantarum especial in carrot juice.

Fermentisani sokovi povrća su važna komponenta ishrane jer se Tokom fermenetacije sintetišu biotičke materije koje poboljšavaju kvalitet prirodnih sokova povrća. Među povrtarskim usevima koji se mogu fermentisati (konzervisati biološkim putem) nalaze se cvekla (Beta vulgaris L.) i mrkva (Daucus carota L.). U ovom radu vršena su uporedna ispitivanja fermentativne aktivnosti sojeva Lb. plantarum A112 i prirodnog izolata Lb. acidophilus BGSJ15-3 u toku mlečno-kiselinskog vrenja soka mrkve i soka cvekle. Aktivnost sojeva bakterija, u toku 8 sati fermentacije, praćena je brojem ćelija, promenom pH vrednosti, sadržajem mlečne kiseline i sadržajem šećera. Rezultati su pokazali da su sok cvekle i sok mrkve dobri supstrati za rast I fermentativnu aktivnost ispitivanih sojeva bakterija mlečne kiseline. Uzimajući u obzir sadržaj sintetisane mlečne kiseline i smanjenje koncentracije glukoze u supstratima, može se zaključiti da Lb. acidophilus pokazuje bolju aktivnost u odnosu na Lb. plantaraum, posebno u soku mrkve. .