Characterisation of chewed/sucked and expectorated raw almonds

• Register: ISRCTN
• Last refreshed on: 13 January 2015
• Main ID: ISRCTN58438021
• Date of registration: 13/11/2013
• Prospective Registration: No
• Primary sponsor: King's College London (UK)
• Public title: Characterisation of chewed/sucked and expectorated raw almonds
• Scientific title: The role of plant cell walls in regulating starch and lipid bioaccessibility from plant foods: in silico, in vivo and in vitro studies
• Date of first enrolment: 15/04/2011
• Target sample size: 15
• Recruitment status: Completed
• URL: http://isrctn.com/ISRCTN58438021
• Study type: Interventional
• Study design: Randomised cross-over design trial (Other)

Countries of recruitment

United Kingdom

Contacts

• Name: Peter Ellis

Key inclusion & exclusion criteria

Inclusion criteria: 1. Be generally healthy
2. Healthy dentition
3. Be at least 18 years old
4. Have eaten almonds with no adverse effects
Exclusion criteria: You must not:
1. Be allergic to nuts of any kind
2. Be allergic to celery, pears, apples, cherries, peaches or parsley
3. Have any teeth missing (apart from unerupted wisdom teeth)
4. Have bleeding gums
5. Had dental treatment (other than checkups) in the last 3 months
6. Be currently suffering from any infectious disease that may be passed on via saliva e.g. Glandular fever, flu
7. Be allergic to wheat, gluten or milk, if chewing the almond muffin meals

Age minimum:
Age maximum:
Gender: Both

Health Condition(s) or Problem(s) studied

Digestion and nutrient bioaccessibility
Nutritional, Metabolic, Endocrine

Intervention(s)

Volunteers are randomly allocated to treatments using an electronic randomisation program

1. Mastication and expectoration of whole raw and roasted almonds.
2. Mastication and expectoration of muffins containing almond flour or almond particles of 2 mm.

Primary Outcome(s)

Measure the size of almond particles that have been chewed sufficiently to be swallowed. Mechanical sieving and laser diffraction are used to measure particle size distribution of the expectorated and digested almonds.

Secondary Outcome(s)

1. Find shape parameters (numerical values) that describe the general particle shape to allow the theoretical model to predict lipid release from intact cells: examined by microscopy (light, scanning electron and transmission)
2. Measure any changes in lipid content and cell-wall polysaccharide composition due to chewing. Quantifying the amount of lipid lost using the Soxhlet method and cell wall changes by gas chromatography.
3. Determine whether cooking almonds affects the release of lipid from the chewed almonds: examined by microscopy (light, scanning electron and transmission)
4. Determine whether lipid is removed from ruptured cells only when in the presence of saliva: examined by microscopy (light, scanning electron and transmission)
5. Determine the effects of chewing on lipid release and cell-wall structure during simulated gastric (stomach) digestion. Quantifying the amount of lipid lost using the Soxhlet method and cell wall changes by gas chromatography.
6. Evaluate how almond incorporated into a complex food structure (muffin) behaves following chewing and simulated digestion. Quantifying the amount of lipid lost using the Soxhlet method and cell wall changes by gas chromatography.

Time points:
1. Baseline (analysis of raw and roasted almonds, and muffins)
2. After mastication
3. During/after gastric digestion (various time points depending on the test food, i.e. almond vs muffin)
4. After duodenal digestion

Chewed almond and muffins are loaded into an in vitro digestion model (Dynamic Gastric Model at the Institute of Food Research in Norwich)

Secondary ID(s)

N/A

Source(s) of Monetary Support

Biotechnology and Biological Sciences Research Council (BBSRC) (UK), reference BB/H004866/1