Probiotic-containing apple wedges may offer dairy-free alternatives

Writing in Innovative Food Science & Emerging Technologies​, researchers from Ireland’s Teagasc report the development of a fresh-cut apple wedges with Lactobacillus rhamnosus​ GG. In all the test samples prepared the bacterial strain was found in sufficient quantities for a probiotic effect, they said.

“[This bacterial count] is comparable to counts of probiotic bacteria in commercially available dairy products,”​ wrote the researchers, led by Christian Roessle.

Roessle told NutraIngredients: “We believe that there would be vast demand for probiotic apple slices as there is an increase in sales for fresh-cut fruit every year. This product will provide an alternative probiotic food choice for consumers. ​

“The process for making this product is relatively simple and the product would retail from the conventional chill counters of supermarket stores.”​

Growth in gut health​

The gut health market is dominated by probiotics and prebiotics. As science continues to expand our understanding of the effects of modulating the intestinal microflora we see that beneficial gut health may only be the tip of the iceberg.

According to the FAO/WHO, probiotics are defined as ‘live microorganisms which when administered in adequate amounts confer a health benefit on the host’.

“[Applying a probiotic bacterium to fresh-cut apple wedges] will provide an alternative probiotic food choice for consumers and could be particularly appealing to children,”​ wrote Roessle and his co-workers.

“The process for making this product is relatively simple and the product would retail from the conventional chill counters of supermarket stores. It is likely that its price would be competitive with existing probiotic dairy products,”​ they added.

The study was described as an “interesting”​ and “well done in vitro study”​ by probiotic expert Professor Gregor Reid from the Canadian R&D Centre for Probiotics at the Lawson Health Research Institute, and The University of Western Ontario.

However, Prof Reid questioned the thinking behind the apple wedges. “I'm not sure why you'd want to do this. If you can buy an LGG drink and dip apples into it then wouldn't people just do that?”​

In response, Dr Roessle said: “We are hoping to commercialise this product as soon as possible. An Irish and an American company showed severe interested in commercialising the product and we are currently in contact to discuss the possibility of a scale-up.”​

Dairy intolerance​

The motivation behind the study was to offer probiotic alternatives to people who are allergic or intolerant to dairy products. They chose LGG due to its commercial availability and an extensive body of science supporting its potential probiotic effects.

Roessle and his co-workers cut apple slices into wedges which still had the apple skin on, and dipped them into an edible solution containing 10 billion colony forming units per millilitre of solution. The wedges were also exposed to an anti-browning agent called Natureseal AS1 (AgriCoat, UK), which is widely by the fresh-cut fruit industry.

The experiment was repeated three times, and on each occasion the LGG count was about 100 million cfu per gram.

“Physicochemical properties of the apple wedges containing LGG compared to the control remained stable over the 10 day period,”​ noted the researchers.

A panel of 25 tasters was then used to measure the sensory aspects of both control and LGG-containing wedges, and a preference for apple wedges containing LGG was expressed by 12, while the other 13 preferred the control wedges.

“Physicochemical and sensory evaluation indicated that dipping apple wedges in a solution containing probiotic bacteria resulted in wedges of acceptable quality with sufficient numbers of LGG adsorbed on to the surface for a probiotic effect,”​ wrote the researchers.

“To increase the possible beneficial effects of probiotic bacteria for the host, it could be combined with an appropriate concentration of prebiotics,”​ they concluded.

Source: Innovative Food Science & Emerging Technologies​
Published online ahead of print, doi: 10.1016/j.ifset.2009.08.016
"Evaluation of fresh-cut apple slices enriched with probiotic bacteria"​
​Author: C. Roessle, M.A.E. Auty, N. Brunton, R.T. Gormley, F. Butler