- Business Economics (1)
- Chair Sensory Science and Eating Behaviour (1)
- HNE Sensory Science and Eating Behaviour (1)
- Sensory Science and Eating Behaviour (1)
- VLAG (1)
- G. Koop (1)
- Marja L. Laine (1)
- Paulina Morquecho-Campos (1)
- K. Nazmi (1)
- Kamran Nazmi (1)
- S. Roffel (1)
- T. Werven van (1)
Impact of food odors signaling specific taste qualities and macronutrient content on saliva secretion and composition
Morquecho-Campos, Paulina ; Bikker, Floris J. ; Nazmi, Kamran ; Graaf, Kees de; Laine, Marja L. ; Boesveldt, S. - \ 2019
Appetite 143 (2019). - ISSN 0195-6663
Cephalic phase response - Olfaction - Salivary protein - Salivation - Smell
Olfactory food cues can induce appetite for similar food products in humans. Odors may thus signal essential information about a foods’ composition such as taste or even macronutrient content and may stimulate specific physiological responses in anticipation of food intake. Several studies have shown that sensory food cues could stimulate saliva secretion. However, potential differences between food odors in their effect on saliva secretion, or the effects of olfactory stimulation on changes in saliva composition remain to be elucidated. To gain more insight, we conducted two studies to determine the influence of various odors, representing different taste qualities (study 1) and macronutrients (study 2), on salivary biomarkers. In study 1, 36 participants were randomly exposed to no-odor, non-food, and odors signaling sweet, savory, and sour taste. In study 2, 60 participants were randomly exposed to no-odor, non-food, and odors signaling carbohydrates, protein, fat, and low-calorie food. For each condition, whole-mouth saliva was collected and saliva secretion rate determined. Furthermore, we determined mouth-watering perception (subjective salivation), visco-elasticity (study 1 only), mucin concentration, α-amylase and lingual lipase activity (study 2 only). For both studies, linear mixed model analyses showed that saliva secretion rate significantly increased by food odor exposure compared to no-odor and non-food conditions. However, no changes in salivary composition were observed. These findings indicate that food odors play a crucial role in anticipatory saliva responses and can thereby affect subsequent eating behavior.
Protease activity measurement in milk as a diagnostic test for clinical mastitis in dairy cows
Koop, G. ; Werven, T. van; Roffel, S. ; Hogeveen, H. ; Nazmi, K. ; Bikker, F.J. - \ 2015
Journal of Dairy Science 98 (2015)7. - ISSN 0022-0302 - p. 4613 - 4618.
Cow - Mastitis - Milk - Protease
Due to the increasing use of automated milking systems, automated detection of clinical mastitis is becoming more important. Various in- or on-line diagnostic tests are in use, but generally suffer from false mastitis alerts. In this study, we explored a new diagnostic approach based on measurement of protease activity using fluorogenic protease substrates, which can be performed on site, at high speed, and at low costs. Samples from cows with clinical mastitis submitted for bacteriological culture at the University Farm Animal Practice were collected during several months and kept at -20°C until protease activity measurement. A reference set of milk samples from clinically healthy cows were collected on 9 different farms and were tested for protease activity directly and after freezing at -20°C to allow for comparison with the samples from clinical cases. The protease activity in mastitic milk samples was significantly higher than in samples from healthy animals. Based on 71 clinical mastitis samples and 180 milk samples from clinically healthy quarters, the area under the receiver-operating characteristic curve was estimated to be between 0.88 and 0.90, and at a threshold of 38 fluorescence per minute the test had a specificity of 0.99 at a sensitivity of 0.58. Protease activity measured in fresh milk from clinically healthy cows was significantly associated with somatic cell count and parity, but not with electrical conductivity, whereas protease activity in milk that had been frozen was statistically significantly associated with all 3 parameters. This study indicates that protease activity measurement as a stand-alone test can be used for detecting mastitis samples, using milk samples that have been frozen. Because protease activity acts in part on a different biological mechanism than somatic cell count or electrical conductivity, this test may increase the accuracy of mastitis diagnosis in combination with currently available in- or on-line tests in automated milking systems.