The study, published in the Journal of Food Science, is the first study to investigate the potential for using mushroom waste products as prebiotics – finding that the low-value harvest by-product has potential to act as a probiotic that could enhance the survival of probiotics during cold storage and may improve the tolerance of probiotics in digestion.
“The bases or stipes of mushrooms, because of their tough texture, have been considered to be a waste product when mushrooms are harvested,” explained the research team – led by Wei-Ting Chou from the National Chung Hsing University, China.
Chou and colleagues noted that the cut-off bases – known as stipes - make up between 25 to 33% of the weight of fresh mushrooms, and they are generally used to make low-economic value animal feed or compost. However, they suggest that this underutilised waste could be bioconverted into value-added products.
“A symbiotic interaction occurred between the microbial bacteria and the polysaccharides from different mushroom wastes, clearly altering the balance of the probiotics … and these mushroom polysaccharides apparently had the capability of retarding the death of the probiotics, allowing them to maintain higher populations during cold storage,” said the authors.
“Furthermore, the tolerance and stabilities of the probiotics in simulated gastric juice and bile acid also were improved significantly when they were supplemented with mushroom polysaccharides.”
The team of Chinese researchers extracted polysaccharides from the waste stipes of a variety of mushrooms – L. edodes stipe (LES), P. eryngii base (PEB), and F. velutipes base (FVB) – before testing the potential prebiotic effects on a probiotics – Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium longum, Streptococcus thermophilus, and Lactobacillus delbrueckii subsp. Bulgaricus – in various cultivation systems and storage periods.
“In addition, we investigated the protective effects of the polysaccharides derived from mushroom wastes by simulating the gastric acidity and bile that probiotic strains encounter,” wrote the researchers.
Chou and his team found that a relatively low concentration (0.1%–0.5%) of polysaccharides from Lentinula edodes stipe, Pleurotus eryngii base, and Flammulina velutipes base enhanced the survival rate of Lactobacillus acidophilus, Lactobacillus casei, and Bifidobacterium longum subsp. longum during cold storage.
“The polysaccharides had synergistic effects with the peptides and amino acids from a yogurt culture to maintain probiotics above 107 CFU/mL during cold storage, and they also had significant protective effects on these probiotics in simulated gastric and bile juice conditions to achieve beneficial effects in the host.”
The mushroom waste, which are cheaper than other sources, could be an important, new, alternative source of prebiotics, said the Chinese team.
“The results showed that polysaccharides extracted from inexpensive mushroom wastes have significant potential for use as prebiotics.”
Source: Journal of Food Science
Volume 78, Issue 7, pages M1041–M1048, doi: 10.1111/1750-3841.12160
“The Applications of Polysaccharides from Various Mushroom Wastes as Prebiotics in Different Systems”
Authors: Wei-Ting Chou, I-Chuan Sheih, Tony J. Fang