Survival of Lactobacillus acidophilus and Bifidobacterium bifidum in Ice Cream for Use as a Probiotic Food

Abstract

Probiotic ice cream was made by fermenting a standard ice cream mix with Lactobacillus acidophilus and Bifidobacterium bifidum cultures and then freezing the mix in a batch freezer. Survival of the L. acidophilus and B. bifidum, as well as beta-galactosidase activity, was monitored during 17 wk of frozen storage at -29 degrees C. After freezing of the fermented mix, bacterial counts were 1.5 x 10(8) cfu/ml for L. acidophilus and 2.5 x 10(8) cfu/ml for B. bifidum. Seventeen weeks after freezing, these counts had decreased to 4 x 10(6) and 1 x 10(7) cfu/ml, respectively. During the same period, beta-galactosidase activity decreased from 1800 to 1300 units/ml. Probiotic ice cream was prepared at pH 5.0, 5.5, and 6.0 to determine consumer preferences and was compared with standard Utah State University "Aggie" ice cream. All samples were strawberry-flavored and were evaluated by 88 judges. The preferred pH of probiotic ice cream, based on overall acceptance, was pH 5.5. We demonstrated that probiotic ice cream is a suitable vehicle for delivering beneficial microorganisms such as L. acidophilus and B. bifidum to consumers. The bacteria can be grown to high numbers in ice cream mix and remain viable during frozen storage.

Synbiotic yogurt-ice cream produced via incorporation of microencapsulated lactobacillus acidophilus (la-5) and fructooligosaccharide

“…As well, the number of free cells decreased by an average of 1.5-2 log cycle at the end of 60 days frozen storage. Hekmat and McMahon (1992) reported that the viability of L. acidophilus in a standard ice cream mix decreased by 2 log cycles after storage for 17 weeks at −29°C. Our results show that decrease in the number of free probiotic cells in all samples occurred at the first 30 days of frozen storage and after that, their viability did not significantly change (p< 0.05).…”

“…Hekmat and McMahon (1992) reported that during 17 weeks of frozen storage of probiotic ice cream, Lactobacillus acidophilus count decreased by two log cycles. Encapsulation of probiotic cells within microcarriers provides a relatively new approach to improve their survival.…”

Aceitação sensorial e caracterização de frozen yogurt de leite de cabra com adição de cultura probiótica e prebiótico

“…acidophilus apresentou brusco declínio (2,6 ciclos logarítmicos) desde a matéria-prima até o 7°d ia de armazenamento; no entanto, após 120 dias reduziu apenas 1,9 ciclos logarítmicos, com diferença estatística significativa entre as avaliações. Decréscimo na mesma proporção foi encontrado por HEKMAT & McMAHON (1992), ao armazenarem frozen yogurt com os mesmos probióticos deste estudo pelo mesmo período. HOLCOMB et al (1991) não observaram evidências de injúria pelo frio em L. acidophilus exposto a -5°C, por 6h, enfatizando a influência do fator tempo/temperatura de exposição do produto na viabilidade desse micro-organismo.…”

“…Alguns estudos (HEKMAT & McMAHON, 1992;INOUE et al, 1998;ALAMPRESE et al, 2005) têm demonstrado que é possível produzir frozen yogurt com adição de probióticos. No entanto, os microorganismos devem sobreviver à estocagem a frio (ALAMPRESE et al, 2005), para assegurar a quantidade mínima satisfatória (10 5 -10 7 UFC g -1 ) (UYSAL et al, 2003).…”

Viability of Probiotics in Frozen Yogurt with different levels of Overrun and Glycerol

“…Probiotics may be defined as the live microorganism which when administered in a sufficient quantity help in improving the health of the host (FAO/WHO, 2001). The minimum concentration of probiotics recommended to attain the desirable health benefits is 10 6 -10 7 CFU/g or mL of food at the time of consumption (Hekmat and Mcmahon, 1992;Gomes and Malcata, 1999;Boylston et al, 2004). Bacteria form Lactobacillus and Bifidobacterium genera are most commonly used as probiotics in dairy products (Mohammadi et al, 2011).…”