Rye’s high satiety properties fit well as a weight-managing food, study says

02-Jul-2017 - Last updated on 03-Nov-2017 at 19:15 GMT

Whole grain rye consumption has been linked to a reduction in the risk of death caused by cardiovascular disease, cancer, respiratory disease, diabetes and various infections. ©iStock

The porous, moisture-absorbent properties of rye products such as bread, flakes and granolas are key to maintaining long-lasting satiety and effective weight management, a Finnish study determines.

Tests to determine the food structure’s impact on satiety found the way rye products were digested had a bearing on how full an individual felt after consumption.

The team identified products requiring the most intense chewing (mastication) effort were not necessarily the most satiating ones.

“The current study was successful in producing various food structures resulting in different oral processing patterns,” said the team led by Dr Saara Pentikäinen, research scientist at the VTT Technical Research Centre of Finland

“They were realistic products with structural differences including ductile and chewy texture (bread), hard and crunchy texture (flakes) and hard, airy, crispy texture (puffs) and a soup-like texture (smoothie).

“Providing textures that result in longer or more intense oral processing is preferable when trying to develop products that would naturally help to control food intake and enhance satiety response.“

The European rye belt

Rye is a cereal grain grown across much of Europe. The main rye belt stretches from northern Germany through Poland, Ukraine, Belarus, Lithuania and Latvia into central and northern Russia.

Rye bread, including pumpernickel, is a widely eaten food in Northern and Eastern Europe. Rye is also used to make crisp bread and Mämmi, a traditional Finnish Easter rye pudding.

Rye-based food is very much a staple of the Scandinavian diet. Foodmakers within the region that produce rye-based products include Fazer, Lantmännen, Leksands, Pagen and Italian food producers Barilla.

Dr Pentikäinen’s team took four wholegrain rye based samples (extruded flakes and puffs, bread and smoothie) with wheatbread included as a control.

Twenty-six females aged 20–40 years were recruited into the mastication study, where food samples were served to the participant in random order, each sample in three portions.

The participants were instructed to chew each portion of sample to the point of swallowing.

The three portions of each sample were masticated in a row and there was break between different samples during which mouth was rinsed with water and the expected satiety rating for each sample was evaluated.

Oral processing was characterised by measuring electrical activity of facial muscles with electromyography.

The participant was then asked to anticipate the satiating capacity of the samples before and after mastication of each food sample using a visual analogue scale (VAS) (0 = not at all satiated, 10 = extremely satiated).

A subgroup of 16 participants also participated in a satiety trial. Here, the participants were asked to eat and drink the test products at their own pace.

Satiety related sensations were evaluated before and right after consuming the test portion and repetitively every 30 min until 210 min after starting point of the consumption using 10 cm visual analogue scales (VAS)

The evaluated sensations were hunger, fullness, satiety, desire to eat and prospective food consumption (“How much would you be able to eat right now?”).

In addition, pleasantness of the test portion was evaluated after consuming the portion. Both trials were conducted during October-December 2015.

Study results

The test showed that the structure of food had an impact on satiety.

During the first hour after a snack consisting of rye bread or rye puffs, the feeling of satiety was more intense than after having rye flakes or a rye smoothie.

“Rye bread and rye puffs have very dissimilar structures - puffs are hard, crispy and crunchy while bread is soft,” the study commented.

“What their structure does have in common is porosity. Porous structure may improve the ability of foods to retain fluid in the stomach, causing the stomach to stretch and signal enhanced satiety.”

The team also found the mastication effort had a bearing on satiety response.

However, the team noted, “there are some food structure related factors that influence both mastication process and postprandial satiety, the mastication process itself not being the mediating factor.”

“Higher palatability also seemed to weaken postprandial satiety response.”

Source: Food Quality and Preference

Published online ahead of print: doi.org/10.1016/j.foodqual.2017.04.011

“Do rye product structure, product perceptions and oral processing modulate satiety?”

Authors: Saara Pentikäinen, Nesli Sozer, Johanna Närväinen, Kirsi Sipilä, Syed Ariful Alam, Raija-Liisa Heiniö, Jussi Paananen, Kaisa Poutanen, Marjukka Kolehmainen.