The team coupled konjak glucomannan (KGM) with pH-sensitive chitosan to create blends known as interpenetrating hydrocolloid networks (IHNs). These IHNs could be incorporated into foods to help consumers feel fuller for longer.
It is now believed the IHNs resulting from glucomannan and chitosan are “promising candidates for the development of satiating ingredients,” the scientists, led by Amparo Lopez-Rubio from the Institute of Agrochemistry and Food Technology (IATA), CSIC in Spain, said.
Glucomannan is the only EFSA approved ingredient with a weight loss claim due to its properties which increase satiety. It has high water-holding capacity.
What are Interpenetrating Hydrocolloid Networks (IHN)?
IHNs are blends of two or more different hydrocolloids which interact with each other simply by being mixed – not necessarily through other linkages such as ionic or chemical.
In the study, the two hydrocolloids KGM and chitosan (a pH-sensitive biopolymer) were blended in various quantities to create different IHNs in film or freeze-dried solutions. These solutions were then tested in both neutral and simulated gastric conditions.
The goal was to better understand KGM and chitosan IHNs, specifically in relation of chitosan molecular weight, the ratios of each ingredient used as well as how sodium carbonate salts could affect formation of IHNs.
Lopez-Rubio and his team then looked at the IHNs’ ability to swell in stomach acid conditions, hence giving a satiated effect for the consumer.
“The interactions between KGM and chitosan IHNs have been thoroughly analysed and correlated with swelling behaviour (in the case of blend films),” the researchers wrote in the journal Food Hydrocolloids.
“These IHNs could be useful for the design of satiating ingredients that would swell at gastric pH values.”
In particular, the team found that when freeze drying KGM/ chitosan solutions with sodium carbonate, the blends with higher KGM content displayed better reactions to pH.
The quality seemed to be a result of the added salt promoting inter and intramolecular interactions related to KGM.
“The blends with higher KGM content, which developed stronger interactions, were the ones which displayed a better pH-dependent behaviour showing low flow consistency values at neutral pH and higher viscosities in acidic media,” the team said.
“Therefore, these compositions are promising candidates for the development of satiating ingredients.”
In their solid state as films, the KGM/ chitosan solutions’ swelling properties also depended on the molecular weight of the chitosan.
Other recent research suggests changing the particle size in emulsions could boost satiety.
Source: Food Hydrocolloids
Volume 60, October 2016, Pages 533–542, DOI: 10.1016/j.foodhyd.2016.04.033
“Development of glucomannan-chitosan interpenetrating hydrocolloid networks (IHNs) as a potential tool for creating satiating ingredients”
Authors: Amparo Lopez-Rubioa, Paula Tarancóna, Laura G. Gómez-Mascaraquea, Marta Martínez-Sanzb, Maria Jose Fabraa, Juan Carlos Martínezc, Susana Fiszmana