Tara Grauwet

KU Leuven | ku leuven

In the context of adequately feeding the rising older population, lentils have an important potential as sources of (plant-based) protein as well as slowly digestible bio-encapsulated starch and fibre. This study evaluated in vitro digestion of protein and starch in lentils under conditions representing the gastrointestinal tract of older adults. B...

Recently, pulse ingredients with (partial) cellular intactness are put forward as promising innovative food ingredients with slowed macronutrient digestibility. This study compared cooking quality and nutrient (starch, protein, and mineral) digestibility/bioaccessibility of lentil-based pasta prepared from 100% raw-milled flour, and by substituting...

The digestion of lipids in the human body has several health and nutritional implications. Lipid digestion is an interfacial phenomenon meaning that water-soluble lipases need to first adsorb to the oil-water interface before enzymatic conversions can start. The digestion of lipids mainly occurs on colloidal structures dispersed in water, such as o...

Processing can affect (bio)chemical conversions in vegetables and can act on their volatile properties accordingly. In this study, the integrated effect of pretreatment and pasteurization on the volatile profile of leek and Brussels sprouts and the change of this profile upon refrigerated storage were investigated. Pretreatments were specifically s...

The rate liming step of bean softening during cooking was evaluated. Red kidney beans (fresh/non-aged and aged) were cooked at different temperatures (70-95 °C) and their texture evolution established. Softening of beans (loss of hard texture) with cooking and increasing cooking temperature was evident at ≥ 80 °C more so for non-aged than aged bean...

Cellular pulse ingredients are increasingly being studied but little knowledge on their proteolysis patterns upon digestion is available. This study investigated a size exclusion chromatography (SEC) approach to study in vitro protein digestion in chickpea and lentil powders, providing novel insights into proteolysis kinetics and the evolution of m...

Lentils are sustainable sources of bioencapsulated macronutrients, meaning physical barriers hinder the permeation of digestive enzymes into cotyledon cells, slowing down macronutrient digestion. While lentils are typically consumed as cooked seeds, insights into the effect of cooking time on microstructural and related digestive properties are lac...

Volatile compounds in foods can witness the occurrence of (bio)chemical reactions, comprising both enzymatic and non-enzymatic reactions, which can be influenced by processing. This study investigated the effect of different pretreatments aimed at either minimizing, realized by a heat treatment, or inducing, realized by a tissue disruptive treatmen...

In vitro digestion studies demonstrate large potential to gain more and quicker insights into the underlying mechanisms of feed additives, allowing the optimization of feed design. Unfortunately, current in vitro digestion models relevant for broiler chickens lack sufficient description in terms of protocols and standardisation used. Furthermore, n...

During adverse postharvest storage of Red haricot beans, the inositol phosphate content, particularly InsP6, decreased significantly, along with a significant increase in InsP5. Using a texture-based classification approach, the InsP6 content in cotyledons was shown an indicator for the extent of hard-to-cook (HTC) development during bean aging. Th...

Pulsed electric fields (PEF) at low field strength is considered a non-thermal technique allowing membrane permeabilization in plant-based tissue, hence possibly impacting biochemical conversions and the concomitant volatile profile. Detailed studies on the impact of PEF at low field strength on biochemical conversions in plant-based matrices are s...

Background In the past decades, the great interest in food digestion research led to a wide array of in vitro digestion (IVD) methods. Each of these methods have the potential of providing specific valuable scientific insights in digestion mechanisms and the rational structural design of foods. Scope and approach This review paper outlines importa...

In this work, plant-based shakes were prepared (5% oil, 6% protein, 1% lecithin, 88% water) (w/w) using two processing techniques (i) only mixing versus (ii) mixing followed by high pressure homogenisation, as well as two processing sequences (i) adding all ingredients together versus (ii) stepwise addition of ingredients. Shakes only mixed consist...

Carrageenan-rich precipitate (CRP) was extracted from gametophyte Chondrus crispus at varying temperatures (22 °C, 45 °C, 90 °C) and time (0.25 h, 2 h, 8 h) at neutral conditions (i.e. without addition of alkali). Lower levels of 3,6-anhydrogalactose were detected in CRPs extracted at room temperature (22 °C) compared to extractions at 45 °C and 90...

(Cellular) pulse powders are being proposed as ingredients for different foods. However, the effect of manufacturing conditions on the properties of those powders remained unknown. Therefore, this study investigated the effect of specific manufacturing conditions (cooking time, application of cell isolation, and drying method) on the composition, m...

Nowadays, pulse flours are ingredients that are more and more used as substitutes in traditional staples (i.e., pasta, bread). In this study, cellular chickpea-flour was used as an ingredient to replace conventional raw-milled chickpea-flour in suspensions and semi-solid purees. The contribution of cellular integrity on in vitro macronutrient diges...

In this work, a multireactor system to study digestion (MuReDi) kinetics is introduced. For this, a custom-made automated system with four independent syringe pumps (BioXplorer 100, H.E.L Group) was acquired. This system consists of multiple, small-scale reactors allowing to study digestion as a function of time and thus to determine digestion kine...

This study investigated the in vitro digestion of purified pea fractions (protein isolate and starch) in sponge cakes when compared to unrefined pea flour and to the whole wheat flour and purified maize starch commonly used in the food industry. Proteins in the wheat cake were hydrolysed more rapidly than those in cakes made with either pea flour o...

Present study investigated the impact of flour preparation and thermal processing on the headspace volatile profile of aqueous suspensions of three different chickpea flour types (non-gelatinised open cell flour, pre-gelatinised open cell flour and pre-gelatinised closed cell flour). Suspensions with non-gelatinised chickpea flour contained higher...

We studied the effect of evolving from static in vitro digestion conditions towards the gradual addition of essential digestive compounds for lipid digestion. Two oil-in-water emulsions were considered: a low (5% w/w) and high (20% w/w) triolein-based emulsion with identical surfactant-to-oil ratio (0.2). Emulsions were subjected to in vitro static...

Emulsions stabilized by a mixture of emulsifiers may show a tailored functionality depending on the compatibility of the emulsifiers employed. This was proposed in a previous work dealing with distinct lipolysis kinetics of citrus pectin (CP) and Tween 80 (TW80) based emulsions. CP provided a fast a high extent of gastric lipid hydrolysis, TW80 pre...

Processing results in the transformation of pulses’ structural architecture. Consequently, digestion is anticipated to emerge from the combined effect of intrinsic (matrix-dependent) and extrinsic (processed-induced) factors. In this work, we aimed to investigate the interrelated effect of intrinsic and extrinsic factors on pulses’ structural archi...

These days, large multivariate data sets are common in the food research area. This is not surprising as food quality, which is important for consumers, and its changes are the result of a complex interplay of multiple compounds and reactions. In order to comprehensively extract information from these data sets, proper data analysis tools should be...

To better understand the migration properties of hybrid carrageenan from the seaweed tissue during carrageenan extraction, the effect of increasing the seaweed surface area by the mechanical disintegration of gametophyte Chondrus crispus chips was studied under various temperature and time extraction conditions. Dried Chondrus crispus seaweed chips...

Chickpea flours are an interesting multifunctional ingredient for different food products. This study investigated the potential of differently processed chickpea flours as alternative thickening agents in an instant soup recipe, replacing potato starch. Dry instant soup powders were compared on bulk density and powder flowability, whereas prepared...

Alkali-free carrageenan extraction was performed on dried (around 1 cm size chips) gametophytic and tetrasporophytic Chondrus crispus at varying time and temperatures. For the gametophyte seaweed (containing κι-hybrid carrageenan and its precursors) the first 24 h extraction at room temperature resulted in an almost unrecoverable amount of carragee...

The occurrence of nonenzymaticbrowning in fruit juices during storage is a major quality defect. It negatively affects consumer acceptance and consumption behavior and determines the shelf‐life of these products. Although nonenzymatic browning of fruit juices has been the subject of research for a long time, the exact mechanism of the nonenzymatic...

The functionality of oil-in-water (o/w) emulsions may be modulated by combining emulsifiers rather than using an individual one. Based on our previous studies, citrus pectin (CP) and tween 80 (TW80) were selected as their emulsions presented different physical stability and in vitro lipolysis kinetics. Hence, our objective was to design and evaluat...

The study of triglycerides gastrointestinal fate is of main importance due to their nutritional and health implications. In this matter, there is a need for a specific, reliable and fast method to quantify lipid digestion products. The HPLC-CAD method developed in this work proposes a fast manner to simultaneously quantify triolein, sn-1,2/2,3-diol...

Background In vitro digestion methods are widely used to investigate the effect of food properties on the hydrolysis of the main macronutrients: starch, lipid and protein. The growing quantity of experimental data calls for strategies to quantitatively compare the effect of food composition and structure on their hydrolysis kinetics. Mathematical m...

Pulses are increasingly being put forward as part of healthy diets because they are rich in protein, (slowly digestible) starch, dietary fiber, minerals, and vitamins. In pulses, nutrients are bioencapsulated by a cell wall, which mostly survives cooking followed by mechanical disintegration (e.g., mastication). In this review, we describe how diff...

This study aims to understand the role of storage conditions (temperature, T and moisture content) in the reactions involved in the cation-pectin-phytate hypothesis, postulated to cause the Hard-to-cook (HTC) defect in beans as influenced by the plasticizing effect of moisture (glass transition (Tg) concept). The enzyme catalysed reactions, demethy...

Attention has been given to more (semi-)dynamic in vitro digestion approaches ascertaining the consequences of dynamic in vivo aspects on in vitro digestion kinetics. As these often come with time and economical constraints, evaluating the consequence of stepwise increasing the complexity of static in vitro approaches using easy-to-handle digestion...

In vitro digestion studies often use animal digestive enzyme extracts as substitutes of human gastric and pancreatic secretions. Pancreatin from porcine origin is thus commonly used to provide relevant pancreatic enzymes such as proteases, amylase and lipase. Rabbit gastric extracts (RGE) have been recently introduced to provide gastric lipase in a...

Over the past years, the shift toward plant‐based foods has largely increased the global awareness of the nutritional importance of legumes (common beans (Phaseolus vulgaris L.) in particular) and their potential role in sustainable food systems. Nevertheless, the many benefits of bean consumption may not be realized in large parts of the world, si...

This research evaluated the impact of the emulsion interfacial composition on in vitro small intestinal lipolysis kinetics with the inclusion of rabbit gastric lipase resulting in a gastric prelipolysis step. O/w emulsions contained 5% triolein (w/w) and 1% (w/w) of the following emulsifiers: sodium taurodeoxycholate, citrus pectin, soy protein iso...

In this study, pectin changes during Red haricot bean storage under high temperature and high humidity conditions were investigated to understand the hard-to-cook (HTC) development from a microstructural point of view. First, to ensure repeatability of the microscopy results, a classification of the fresh and stored beans (aged at 35 °C and 83% rel...

Pulse seeds are nutritious and sustainable matrices with a high level of intrinsic microstructural complexity. They contain high‐quality plant‐based protein and substantial amounts of slowly digestible starch and dietary fiber. Starch and protein in pulses are located inside cotyledon cells that survive cooking and subsequent mechanical disintegrat...

Background: It is generally accepted that gastric lipase preferentially cleaves the sn-3 position of triglycerides. Gastric lipase stereospecificity studies have mainly focused on detecting the enantiomeric diglycerides produced from the hydrolysis of the sn-1/3 positions by means of laborious and expensive chromatographic methods. However, other p...

Background: Scientific studies about the impact of emulsion design properties, especially the interfacial composition, on gastric lipid digestion are scarce. A deep understanding of this impact would allow the rational design of tailored emulsion-based products for a controlled lipid hydrolysis. Therefore, the emulsion stability during gastric dige...

Common bean cotyledons are rich in minerals (Mg, Ca, Fe and Zn), but they also contain natural barriers that can potentially prevent mineral absorption during digestion. In this study, both the cell wall integrity and mineral chelators/antinutrients (phytic acid and pectin) were investigated as natural barriers in common bean cotyledons. To examine...

Mineral (Mg, Ca, Fe and Zn) bioaccessibility in common beans was evaluated taking into consideration the common bean food chain from postharvest storage over processing (soaking and cooking) until consumption. Beans were stored at realistic tropical conditions (35 °C and 80% RH) which resulted in already significantly different cooking behavior aft...

In this work, we report on the effect of the emulsion interfacial composition on the lipid digestion kinetics of in vitro gastric lipolysis. Emulsions (o/w) were formulated with triolein (5%, w/w) and emulsifiers of different chemical nature (1%, w/w). These emulsifiers included different low-molecular-weight surfactants: sodium taurodeoxycholate (...

When pulse seeds from a single batch are cooked, considerable variability of hardness values in the population is usually observed. Sorting the seeds into hardness categories could reduce the observed diversity and increase uniformity. Therefore, we investigated the effect of processing intensity whether or not combined with sorting into hardness c...

This investigation reports the effect of droplet size behavior on the overall lipolysis profile and molecular lipolysis mechanisms under in vitro gastric conditions. O/W emulsions (5% triolein, 1% sodium taurodeoxycholate) with different initial droplet sizes (fine: 0.58 μm; medium: 1.82 μm; and large: 4.00 μm) were subjected to static in vitro dig...

Postharvest storage of legumes is one strategy to ensure food security. However, the hard-to-cook phenomenon, partly explained by the pectin-cation-phytate theory, may develop during storage. Based on this theory, minerals could be redistributed within the matrix, affecting the concentration of free/bound minerals and hence their bioaccessibility....

The incorporation of microalgae into processed food products is considered a sustainable strategy to enrich food products in omega-3 long chain polyunsaturated fatty acids (ω3-LC-PUFA). However, the microstructural properties of the microalgae might influence the nutrient digestibility and bioaccessibility during consumption. The current study prov...

Nutrients are bio-encapsulated by different structures in plant-based foods, which can behave as digestive barriers upon consumption. These natural barriers can be modified during food processing (e.g. thermal and mechanical treatments). On the one hand, processing can be applied to fully disrupt naturally present barriers, while on the other hand,...

In view of reducing synthetic antioxidants in emulsion-based food products, such as ethylene diamine tetraacetic acid (EDTA), this study aimed to investigate the simultaneous use of low methylesterified citrus pectin and EDTA to inhibit lipid oxidation as a consequence of their capacities to chelate Fe²⁺. EDTA was found to be more effective in redu...

This study focused on investigating quality changes of thermally processed kale purée using an integrated targeted and untargeted approach. Low, medium, and high processing intensities (carried out at 70, 90, and 128 °C) were selected based on predetermined shelf-life targets: frozen-thawed, refrigerated, and ambient storage, respectively. The resu...

In this study, we evaluated the effect process-induced common bean hardness on structural properties of in vivo generated boluses and the consequences for in vitro starch digestion. Initially, the impact of human mastication on the particle size distribution (PSD) of oral boluses from common beans with different process-induced hardness levels was...

This work presents that lipid digestion kinetics of oil-in-water emulsions can be described by a mechanism-based multiresponse model. The modelling approach proposed takes into account multiple interlinked responses of in vitro lipolysis. Different reaction schemes are proposed and iteratively adapted for one dataset. Based on model discrimination,...

The cognition of original qualitative attributes of native Peruvian chili peppers elucidate their potential industrial exploitation. There is a lack of scientific information about chili pepper physicochemical and nutritional attributes, that hampers their immediate industrial use. Therefore, the aim of the present study was to characterize twenty...

The impact of low-oxygen spiral-filter press technology combined with thermal pasteurization (TP), pulsed electric field (PEF) and high pressure processing (HPP) on cloudy apple juice quality was investigated immediately after the treatments and after 3 weeks of storage at 4 °C. Based on equivalent levels of microbial safety and desired shelf-life,...

Particular storage conditions are described to promote the development of the hard-to-cook (HTC) phenomenon for most legumes. However, it is not clearly established whether the HTC phenomenon influences starch digestion kinetics. Therefore, this study explored how the HTC phenomenon influences in vitro starch digestion of Bambara groundnuts, taking...

Plant-based foods gain more importance since they play a key role in sustainable, low-meat and healthy diets. In developing countries, these food products, especially legumes and cereals, are important staple foods. Nevertheless, the question arises on how efficient they are to deliver minerals and if it is useful to encourage their consumption to...

Minerals are required by the human body to perform physiological functions. Mineral deficiencies, often caused by low mineral bioaccessibility in plant-based foods, are a matter of great concern all over the world. Several mineral antinutrients (e.g. pectin) may contribute to this reduced mineral bioaccessibility by formation of indigestible comple...

The presence of cell walls entrapping starch granules in common bean cotyledons, prevailing after thermal processing and mechanical disintegration, has been identified as the main reason for their (s)low in vitro starch digestibility. Nevertheless, it is unknown if the role of cell walls on starch digestion changes as processing conditions (e.g. ti...

The aim of this work was to study the formation of lipid nanoparticles (LNPs) with low (corn and olive oil) or high temperature melting lipids (cocoa butter and hydrogenated coconut oil). Moreover, their β-carotene stability and in vitro digestibility kinetics was evaluated. Submicron LNPs (d43 ≈ 570–780 nm) were stabilized with Tween 80 at a surfa...

Pectin is an anionic cell wall polysaccharide which is known to interact with divalent cations via its nonmethylesterified galacturonic acid units. Due to its cation‐binding capacity, extracted pectin is frequently used for several purposes, such as a gelling agent in food products or as a biosorbent to remove toxic metals from waste water. Pectin...

Beans age during storage leading to prolonged cooking times. Chemical reactions that occur during cooking lead to volatile production and flavor generation. Whereas few studies profiled the volatile fingerprint of either non-cooked beans or beans cooked for a specific time, this study explored the evolution of volatiles through headspace fingerprin...

Dynamics of pectin extractability in cotyledons and seed coats were explored for mechanistic insight into pectin changes due to aging and cooking of beans. In addition, changes in mineral distribution during cooking were determined in order to investigate their retention in the matrix. Pre-soaked fresh and aged beans were cooked in demineralized wa...

The present work focused on the (i) physical characterization of the emulsion stabilizing potential of citrus pectin (CP) with different degree of methylesterification (DM; CP82, CP38 and CP10) and (ii) evaluation of interactions that occur between CP and conventional emulsifiers (Tween80 and phosphatidylcholine) used for emulsion stabilization. Fi...

The role of molar mass in determining Ca²⁺-ion maximum adsorption capacity of polygalacturonic acid (PGA) and low methylesterified citrus pectin (CP) as well as their interaction energy was established through equilibrium dialysis followed by colorimetric determination of free ions. Modeling of the moles of Ca²⁺-ions bound per mole of galacturonic...

An integrated science-based approach, combining analytical and sensorial data and different data analysis methods, proved successful to study the impact of storage time, storage temperature and oxygen availability on strawberry juice volatiles and allowed to get a multi-perspective view on these changes. An untargeted GC–MS approach showed that the...

Insight into the effect of the degree and pattern of methylesterification of citrus pectin on the Ca²⁺ and Zn²⁺ adsorption capacity and the associated Zn²⁺ bioaccessibility was established. Pectins with comparable methylesterification degrees (DM) but different patterns of methylester distribution (blockwise or random) were generated. Blockwise dis...

Micronutrients such as minerals are required by the organisms to perform physiological functions in the body. The prevalence of mineral deficiencies is a matter of great concern all over the world and it can be caused due to the low mineral bioaccessibility from plant-based foods. Moreover, presence of several anti-nutrients (e.g. pectin) may caus...

Emulsions (d43 0.484–0.897 μm) and nanoemulsions (d43 0.279–0.226 μm) based on lipid fractions enriched with carotenoids from different sources were produced by increasing the amount of a non-ionic surfactant (Tween 80) at surfactant-to-oil ratio (SOR) 0.1 or 2, respectively. Alternatively, carrot purée in situ emulsions were fabricated by processi...

A broad range of Peruvian chili peppers are available but not properly characterized. To increase the insight into their flavor compounds, a head space GC–MS fingerprinting (volatiles) and an HPLC-based profiling approach (pungency) was implemented to characterize twenty landraces (Capsicum annuum, C. baccatum and C. chinense). The data obtained wa...

Oil-in-water emulsions were prepared with 5% (w/v) carrot-enriched olive oil and stabilized with Tween 80 (TW), phosphatidylcholine (PC), citrus pectin (CP) or a combination of these emulsifiers. Additionally, the methylesterification degree (DM) of citrus pectin was modified, resulting in three different studied pectin structures: CP82, CP38 and C...

Background: Defining the exact shelf-life of a shelf-stable food product is still a real challenge for food manufacturers as there are many variables to be considered. Currently, many shelf-life determinations of commercial shelf-stable products are based on trial-and-error methods which could pose risks resulting in brand damage (overestimation) o...

Emulsions were prepared with oils (5% w/v) differing in unsaturation degree (olive, soybean or linseed oil) and sucrose ester (0.5% w/v) used as emulsifier. The oils studied were enriched with carotenoids from carrot or tomato purees. All emulsions were in vitro digested and characterised at the level of lipolysis and carotenoid micellarisation kin...

The potential use of water-soluble biopolymers from vegetable-origin in structuring oil-in-water emulsions and the influence on their digestion was investigated. The aqueous/serum phase, containing water-soluble biopolymers, of processed carrot and broccoli purées were isolated, lyophilized and then used either as the emulsifier or component in the...

In the fruit juice industry, high pressure (HP) processing has become a commercial success. However, enzymatic browning, cloud loss, and flavor changes during storage remain challenges. The aim of this study is to combine kiwifruit puree and HP pasteurization (600 MPa/3 min) to stabilize cloudy apple juice during storage at 4 °C. A wide range of ta...

The relative contributions of cotyledons and seed coats towards hardening of common beans (Phaseolus vulgaris) were investigated and the rate-limiting process which controls bean softening during cooking was determined. Fresh or aged whole beans and cotyledons were soaked and cooked in demineralised water or 0.1 M NaHCO3 solution, and texture evolu...

Background: Accurate shelf-life dating of food products is crucial for consumers and industries. Therefore, present work applied a science-based approach for shelf-life assessment, including accelerated shelf-life testing (ASLT), acceptability testing and the screening of analytical attributes for fast shelf-life predictions. Shelf-stable strawber...

In common beans, starch is enclosed by natural (micro)structural barriers influencing its behaviour during processing and digestion. Such barriers and their process-induced modifications could modulate nutrient delivery if adequate processing variables could be selected. In this study, the potential of different processing variables for generating...

Cloud loss, enzymatic browning, and flavor changes are important quality defects of cloudy fruit juices determining consumer acceptability. The development of clean label options to overcome such quality problems is currently of high interest. Therefore, this study investigated the effect of kiwifruit puree (clean label ingredient) and high pressur...

Oil-in-water emulsions were prepared with carrot- or tomato-enriched olive oil (5%w/v) and stabilized with Tween80 or sucrose esters (0.5%w/v) with different hydrophilic-lipophilic balance (8; 11 or 16). All emulsions had similar initial oil droplet sizes and were submitted to simulated gastrointestinal conditions using a kinetic digestion procedur...

The micellar incorporation of carotenoids (lycopene, α- and β-carotene) and lipid digestion products (free fatty acids, FFAs, and monoacylglycerides, MAGs) during in vitro digestion of oil-in-water emulsions was investigated by a kinetic approach. A fractional conversion model could adequately describe the hydrolysis of triacylglycerides, formation...

Colour changes during storage are an important quality defect of fruit-based products. Therefore, this work investigated the effect of storage time, storage temperature and oxygen availability (through the type of bottle) on changes in CIEL*a*b values, anthocyanin and ascorbic acid content of shelf-stable strawberry juice (produced with a spiral-fi...

The present work explored the lipid antioxidant capacity of citrus pectin addition to 5%(w/v) linseed/sunflower oil emulsions stabilized with 0.5%(w/v) Tween 80, as affected by pectin molecular characteristics. The peroxide formation in the emulsions, containing tailored pectin structures, was studied during two weeks of storage at 35°C. Low demeth...

The present study aimed at gaining insight into the potential of citrus pectin to bind Fe²⁺, a cation of great importance in several food products. In particular, the role of citrus pectin structural properties, namely the degree of methylesterification (DM) and the absolute degree of blockiness (DBabs – ratio of non-methylesterified GalA units pre...

Carotenoid-enriched oil-in-water emulsions with different droplet sizes (small: d43 0.72 μm; medium: d43 1.9 μm; large: d43 15.1 μm) were subjected to simulated gastrointestinal conditions. The kinetics of lipolysis, micelle formation and carotenoid bioaccessibility were monitored during the intestinal phase. The rates of all three processes increa...

The aim of this study was scientifically investigate the impact of the sequence of different thermo-mechanical treatments on the volatile profile of differently processed broccoli puree, and to investigate if any relationship persists between detected off-flavour changes and microstructural changes as a function of selected process conditions. Comp...