How low can you go (gebaseerd op AF-17026)
The daily intake of sodium, sugar, and fats by modern western consumers, looking for convenience in preparation combined with the increasing snacking trend, is too high. This leads to health issues and rising costs of healthcare. In many countries, both the food industries and consumers have pledged to make western diets healthier. However, the assortment of processed foods meeting nutrition and health requirements is still small and available products do not often meet convenience and expectations.
To achieve breakthrough innovations in the following areas:
1. fundamental insights into the functional role of ingredients and their interactions in the complex food matrix during processing,
2. physical and chemical based models that link (thermo-dynamical) ingredient properties and ingredients composition to the mechanical and sensorial properties of food,
3. fundamental insights into the role of stevia derived glycosides and their interactions with other sugars, sweeteners and enhancers on sweetness perception and metabolism.
Using state-of-the-art technologies two work packages are defined, being
WP1: Functionality of stevia derived glycosides
WP2: Ingredient interactions and processing in complex food matrices
The proposed project aims at developing new strategies for developing convenient and healthy(e.g. sugar and/or fat reduced) foods (impact for food sector and society) allowing food manufacturers (impact for the food sector) to produce new food products that meet convenience, shelf-life, nutrition, health and preference requirements (impact for the society) and will be successful on the market. The following deliverable is intended:
Knowledge-based strategies to create foods with a healthier formulation while meeting consumer’s expectations
WP1.2 Finalize testing of current samples with sweet and bitter receptor assays and proceed with new samples if needed.
WP1.3 Optimize further the saliva/mucus experimentations
WP1.4 Study health effects of stevia glycosides in the intestinal tract using several different in vitro cell culture assays.
WP 2.2: Continue characterization of product properties during the snack preparation phases at standard conditions and development NIR technique to measure water profiles.
WP 2.3: Continue impact of ingredients and crumb production process on crumb performance running
WP 2.4: Continue effect of processing steps in snack preparation chain on crumb sensory properties.
WP 2.5: Continue effect of batter/barrier and substrate properties on crumb sensory properties
WP 2.6: Start integrated application of new developed concepts
WP 2.7: Start sensory and consumer studies
WP 2.8: Continue development and validate mechanistic model
b. results incl publications
WP 1.2: Spray-dried stevia glucosides-containing sweetener products, to be used in formulations of consumer products, have been evaluated in various concentration series. Evaluation was based on different in vitro sweet-receptor cell assays, in order to study receptor interaction mechanisms, time of onset, degree of stimulation and time-intensity profiles. Results have been compared with test result of single sugar/sweetener samples (such as glucose, fructose & sucrose; erythritol & RebA). Next to that we analyzed the first-generation of glycoside emulsion-based formulations that were provided and developed by the project partner. Results have revealed very interesting insights in the potential mechanism of sweet receptor activation and how the producer can optimize the product sweet perception based on this knowledge.
Effort has been put in designing and setting up two types of bitter receptor screening assays. Validation of the assays showed that unfortunately, one assay doesn’t respond to bitter-tasting positive control samples known to interact with this receptor. The second assay seems to work, as validated with an ionophore positive control sample. However the assay needs further optimization, as the sensitivity of the assay seems too low for the bitter receptor-interactions that we would like to study.
WP1.3: In 2019, saliva was collected from volunteer’s. In combination with commercially purchased mucus, we tried to integrate a mucus-saliva layer in our existing sweet receptor screening assay, to study the migration of stevia glycosides through the mucus layer, before it reaches the sweet receptor. Integration of such a layer on top of the cell culture monolayer was successful, however the mucus layer prevented loading/detection of the calcium fluorophore that is needed for the read-out of the sweet receptor assay. Also, the addition of only saliva to the cell culture layer seemed to already activate the calcium fluorophore in absence of a sweet compound. It was therefore decided not to continue with the development of such an assay.
WP1.4: Due to COVID-19 restrictions in the building and the cell culture lab, we were not able to start yet with applying different in vitro cell culture assays to study the health effects of stevia glycosides in the intestinal tract. However, an extensive literature study has been carried out into the different cell assay growth conditions possibilities to study stevia metabolism in the small intestine (sugar metabolism and hormone regulation) as well as in the large intestine (microbiome fermentation), and different experimental set-ups have been proposed and discussed with the project partner. These experiments have now been schedules for early 2021.
WP 2.2: Various products differing in types of crumb and coating were characterized during the whole snack production chain from crumb application, pre-frying, freezing, storage and final heating in the microwave. Measured properties include water contents and water activities of the different snack components (substrate, coating, crumb) at different stages in the production chain, including storage in freezers at -20oC to monitor shelf life. From experiments in 2019 it was concluded that water transport mechanism during storage at -5oC is different than during storage at -20oC, implying that it seems not possible to increase the speed of a shelf-life test by increasing the storage temperature during freezing. Sound and fracture characteristics of the crumbs was used as a measure for crispness.
Together with Biometris a technique is under development using Near InfraRed Multispectral Imaging and Image Analysis to measure water and fat content profiles in these snacks.
Furthermore, the effect of microwave heating on final crumb properties have been investigated.
WP 2.3: Different types of crumbs, produced using different formulations, are characterized during the snack production process and compared to that of the reference. Furthermore, the history of crumb drying was also tested. The hypothesis was that slow drying of the crumb would lead to a lower free volume compared to fast drying. This would than result in slower water uptake during storage. However, experimental results show large variation and this hypothesis could not be confirmed.
WP 2.4: Substrate, coating and crumbs are followed during the production chain. From this it became clear that certain process steps, like coating and freezing after pre-frying have a large impact on crumb moisture content. A study to has been performed to the effect of speed of freezing after prefrying and before storage. Experimental results show large variation and no clear difference in performance between different freezing techniques could be observed.
WP 2.5 Products with different coatings are studied. From XRT it was found that certain coating showed more cracks than others.
WP 2.7: The sensory studies to gain insight in the effect of processing steps in snack preparation chain on crumb sensory properties has been moved to 2021.
WP 2.8: A mechanistic models based on the thermo-dynamical description of water transport in polymeric porous and non-porous systems has been developed to describe the water transport during the whole production chain of the whole product and compared with experimental data. Further validation is planned for 2021