Microbial safety and probiotic potential of packaged yogurt products in Pakistan

Abstract

Yogurt is a health food with notable market production and demand. Because of this, we conducted a study on prominent commercial brands of yogurts in Pakistan for microbial content and the probiotic potential of the contained lactic acid bacteria (LAB), in the context of their label claims. All contained viable LAB, but the numbers (cfu g −1 ) varied considerably. Three of the products made explicit probiotic claims, but LAB from these displayed no probiotic attributes per WHO-FAO guidelines. The yogurt starter and nonstarter Lactobacillus strains had no gelatinase or hemolytic activity and exhibited significant antibacterial activity against some human pathogens. One brand with a probiotic claim contained an L. acidophilus strain that showed cholesterol assimilation activity in vitro. Some potential human pathogens that were hemolytic and resistance to β-lactam antibiotics were also detected in the products. The findings demonstrate a need for better quality control and regulation to ensure safety and efficacy of yogurt products.Values are mean of three replicates. ‡ LAB isolated on MRSc and M17 media. | Non-LAB isolated on nutrient and MacConkey media. § Genus and species-specific primers for Lactobacillus, Bifidobacterium, Lactobacillus delbrueckii, Lactococcus lactis, and Streptococcus thermophilu. ¶ Expiry and manufacturing date and contact information provided except lot/batch number. **a: de Man, Rogosa and Sharpe (MRS) medium supplemented with L-cysteine in anaerobic condition; b: M17 in aerobic conditions. † † Neg for the primers used.

Probiotic Properties of Lactobacillus helveticus and Lactobacillus plantarum Isolated from Traditional Pakistani Yoghurt

“…paracasei , L. bulgaricus , L. delbrueckii , L. plantarum , Lactobacillus fermentum , Lactobacillus rhamnosus , and Streptococcus thermophilus from Faisalabad [ 20 – 24 ]; L. bulgaricus from Islamabad [ 25 ]; Pediococcus pentosaccus , L. delbrueckii , L. plantarum , L. helveticus , and Pediococcus acidilactici from Peshawar; and Lactobacillus curvatus KIBGE-IB44 from Karachi [ 26 , 27 ]. These microbes are also included in commercial probiotic yoghurt in Pakistan [ 28 ]. In Pakistan, L. helveticus and L. plantarum are rarely isolated from yoghurt as compared to other species; thus, their probiotic potential is barely determined.…”

Антибіотики Та Антибіотикорезистентні Властивості Мікроорганізмів Молока

“…Крім того, повідомляється, що у йогуртах паралельно можуть виявлятись деякі потенційні патогени людини, які володіють гемолітичними властивостями та стійкістю до до β-лактамних антибіотиків [48].…”