Short communication: Viability of culture organisms in honey-enriched acidophilus-bifidus-thermophilus (ABT)-type fermented camel milk

Abstract

The aim of this research was to monitor the survival during refrigerated storage of Lactobacillus acidophilus LA-5 (A), Bifidobacterium animalis ssp. lactis BB-12 (B), and Streptococcus thermophilus CHCC 742/2130 (T) in cultured dairy foods made from camel and, for comparison, cow milks supplemented with black locust (Robinia pseudoacacia L.) honey and fermented by an acidophilus-bifidus-thermophilus (ABT)-type culture. Two liters of dromedary camel milk and 2 L of cow milk were heated to 90 °C and held for 10 min, then cooled to 40 °C. One half of both types of milk was fortified with black locust honey at the rate of 5.0% (wt/vol), whereas the other half was devoid of honey and served as a control. The camel and cow milks with and without honey were subsequently inoculated with ABT-5 culture and were fermented at 37 °C until a pH value of 4.6 was reached. Thereafter, the probiotic fermented milks were cooled to 15 °C in ice water and were each separated into 18 fractions that were transferred in sterile, tightly capped centrifuge tubes. After 24 h of cooling at 8 °C (d 0), the samples were stored at refrigeration temperature (4 °C). Three tubes of all 4 products (i.e., fermented camel and cow milks with and without honey) were taken at each sampling time (i.e., following 0, 7, 14, 21, 28, and 35 d of storage), and the counts of characteristic microorganisms and those of certain spoilage microbes (yeasts, molds, coliforms, Escherichia coli) were enumerated. The entire experimental program was repeated twice. The results showed that addition of black locust honey at 5% to heat-treated camel and cow milks did not influence the growth and survival of starter streptococci during production and subsequent refrigerated storage of fermented ABT milks. In contrast, honey improved retention of viability of B. animalis ssp. lactis BB-12 in the camel milk-based product during storage at 4 °C up to 5 wk. No spoilage organisms were detected in any of the samples tested in this study. In conclusion, supplementation of cultured dairy foods, especially those made from camel milk, with honey is recommended because honey is a healthy natural sweetener with a variety of beneficial microbiological, nutritional, and sensory properties.

Effect of genetic and nongenetic factors on chemical composition of individual milk samples from dromedary camels (Camelus dromedarius) under intensive management

“…Small-scale farms in Australia, Europe, and the United States have also started using milking machines for dromedaries. As a result, more and more raw milk is processed and new camel milkbased products are developed and marketed worldwide (Varga et al, 2014).…”

Investigation of the rheological, microbial, and physicochemical properties of developed synbiotic yogurt containing Lactobacillus acidophilus LA‐5, honey, and cinnamon extract

“…(2008), and Varga et al. (2014). The selectivity of honey as a substrate for the probiotic bacteria is an important aspect of the prebiotic effect that may depend on the probiotic strain.…”

“…The selectivity of honey as a substrate for the probiotic bacteria is an important aspect of the prebiotic effect that may depend on the probiotic strain. Although the 5% wt/vol of honey supported the viability of for lactobacilli and bifidobacteria, the viability of bifidobacteria was higher than lactobacilli (Macedo et al., 2008; Popa & Ustunol, 2011; Varga et al., 2014).…”

Effect of Food Composition on Probiotic Bacteria Viability

“…Recently, Varga et al (2014) reported that the addition of honey (5%) to camel milk enhanced the viability of B. animalis ssp. lactis during cold storage in co-cultured fermented milk.…”