Super fruit may boost shelf-life for probiotic yoghurt

Adding the pulp of acai to probiotic yoghurt may boost the shelf-life of probiotic yoghurt, as well as improving the fat profile of the functional food, says a new study.

The levels of one Lactobacillus strain and two Bifidobacteria strains in a yoghurt increased over the course of four weeks in cold storage, while the monounsaturated and polyunsaturated fatty acid content of the product also improved on addition of the açai pulp, according to new findings from Brazil published in the International Dairy Journal.

Açai berries (pronounced ah-sigh-ee) have long formed part of the staple diet of Indian tribes. With the appearance of a purple grape and taste of a tropical berry, it has been shown to have powerful antioxidant properties thanks to a high level of anthocyanins, pigments that are also present in red wine.

It is presently being sold in a number of countries, including New Zealand, Australia, South America, Japan, USA, and the Middle East.

“This study demonstrated that the production of bioactive lipid components such as alpha-linolenic and conjugated linoleic acids can be enhanced by açai pulp addition during fermentation of skim milk prepared with B. animalis ssp. lactis Bl04 and B94 strains, offering potential health benefits of this probiotic açai yoghurt,” wrote the researchers, led by Marice Oliveira from Sao Paulo University.

The new research taps into the health and wellness trend and ticks not one but two boxes – probiotics and super fruits. According to Euromonitor International, the value of the global probiotic market, including yoghurt, supplements and juice, was over $20bn (€14.2bn) in 2008. But there is currently an emphasis on the European market, in which the market analysts said that probiotic yoghurt alone was worth $6.73bn (€4.8bn) last year.

The US probiotics market is still considered to be relatively immature compared to Europe, although it is growing rapidly. In 2008, Datamonitor valued the US market for probiotics at about $1.5bn (€1.06bn), up from $952m (€674m) five years earlier.

Study details

Oliveira and his co-workers used skim milk to prepare a range of yoghurts with starter cultures and four probiotic cultures: L. acidophilus (DSM), B. animalis subsp. lactis BL04 (Danisco) and B94 (DSM), and B. longum 120 (Danisco). Yoghurts were prepared with or without the addition of the fruit pulp.

According to the results, the açai pulp was associated with increased cell counts of L. acidophilus L10, B. animalis ssp. lactis Bl04 and B. longum Bl05 after four weeks.

In addition, “all açai yoghurts showed higher content of monounsaturated fatty acids (MUFA) and PUFA compared with their controls without pulp. On the other hand, yoghurts without açai showed the highest content of saturated fatty acids”, added the researchers.

Source: International Dairy Journal

Published online ahead of print, doi: 10.1016/j.idairyj.2010.01.002

“Açai pulp addition improves fatty acid profile and probiotic viability in yoghurt”

Authors: A.P. do Espirito Santo, R.C. Silva, F.A.S.M. Soares, D. Anjos, L.A. Gioielli, M.N. Oliveira