Search

Water retention is an important quality attribute for yogurt. Classically, stirred yogurt water retention is investigated using induced syneresis measurement (centrifugation), which does not characterize spontaneous syneresis. Low-frequency nuclear magnetic resonance (1H-LF-NMR) is a non-destructive technique to detect spontaneous syneresis. Experimental yogurt from pasteurized skim milk, and commercial stirred yogurts were analyzed with 1H-LF-NMR. After Laplace's transformation of the signal, hydrogen atoms pools were differentiated according to their mobility. Each hydrogen pool stood for a type of water mobility in the matrices characterized by a relaxation time (T2(i)), and a signal intensity (I2(i)). Yogurt water retention was assessed by induced syneresis and their structure was characterized using microscopy. Low frequency 1H-NMR detected four different water mobility groups in the matrices. Among these, there was a signal from bulk water, and another attributed to the separated serum (spontaneous syneresis). In experimental yogurts, spontaneous syneresis was visible, resulting in induced syneresis higher than 50%. Moreover, induced syneresis and spontaneous syneresis detected by 1H-LF-NMR were similar. In commercial yogurts, bulk water mobility reduced with increasing protein content and protein network density. Induced syneresis and bulk-water mobility correlated only in yogurts without gelatin. In the presence of gelatin, the network was more open, probably favoring bulk water mobility. This study shows that 1H-LF-NMR associated with microscopy image analysis efficiently assesses and describes yogurts water retention and spontaneous syneresis.

Solid food disintegration in the stomach has recently been linked to food texture, which changes during digestion. This phenomenon is likely to affect the kinetics of protein digestion and therefore associated postprandial metabolic responses. Depending upon the variety, the cheese protein and lipid content as well as the texture can be modulated, illustrating complexity. Five commercial cheeses, covering a range of textural properties, were selected and characterised. Cheese particles were submitted to an in vitro digestion model to study cheese disintegration and protein/peptide release. Cheese disintegration was affected by cheese texture and composition. At the end of gastric digestion, elastic cheeses (mozzarella) were less disintegrated when compared with ripened and soft cheeses with high fat content (Camembert, aged Cheddar). The protein digestion was different amongst cheeses according to different disintegration rates. Cheese structural and textural properties, attributed to processing parameters, can be used to modulate gastro-intestinal digestion of cheese proteins.

Blueberry composition was characterized for 6 cultivars. It contains a good amount of dietary fiber (10% to 20%) and pectin (4% to 7%) whose degree of methylation (DM) is sensitive to food processing. A low temperature blanching (LTB: 60 °C/1 h) was applied on blueberry purees to decrease pectin DM, in order to modulate puree properties and functionalities (that is, viscosity and stability), and to enhance pectin affinity toward other components within food matrices. Fiber content, viscosity, pectin solubility, DM, and monosaccharide composition were determined for both pasteurized, and LTB+pasteurized blueberry purees. The results showed that neither the amount of fiber, nor the viscosity were affected by LTB, indicating that this treatment did not result in any significant pectin depolymerization and degradation. LTB caused a decrease both in pectin DM from 58–67% to 45–47% and in the amount of water-soluble pectin fraction, the latter remaining the major fraction of total pectin at 52% to 57%. A LTB is a simple and mild process to produce blueberry purees with mostly soluble and low-methylated pectin in order to extend functionality and opportunities for interactions with other food ingredients.

Cheese characteristics, such as composition or textural properties, can impact the matrix degradation rate which could modulate the bioaccessibility of fatty acids during digestion. The aim of this study was to identify texture parameters influencing cheese degradation in a gastrointestinal environment. A static in vitro digestion model has been used on nine commercial cheeses: young and aged cheddar, regular and light cream cheese, parmesan, feta, camembert, mozzarella, and sliced processed cheese. At the end of gastric digestion, camembert and mozzarella presented the lowest matrix disintegration whereas aged cheddar, regular and light cream cheeses showed the highest. For all cheeses, the fatty acid release was fast during the first 30 min of duodenal digestion and slowed down afterwards. A partial least square regression revealed that springiness, cohesiveness, and hardness were negatively correlated to the rate of cheese disintegration during gastric digestion. In addition, textural parameters were not correlated with free fatty acid release. By modulating cheese texture, it could be possible to influence matrix disintegration during gastrointestinal digestion which could have an impact on lipids release.

Seaweeds have a long tradition in Asian cuisine. In Canada and US, seaweed consumption is mostly limited to sushi and other imported Asian dish. However, seaweeds are well recognized for their richness in several nutrients such as fiber, protein and minerals. But what is limiting seaweed and seaweed derived ingredients utilization in home cooking? Finding fresh seaweeds within inland cities is one limiting step but also the seaweed marketing need to propel the image that seaweed are not only nutritive but can bring flavor and texture in cuisine dish. With the rise of TV cooking shows, blogs and online recipes hosted by several renowned chefs, it is now time to bring seaweed in the spotlight. The aim of this review is to look at seaweeds to support a wider use in culinary applications for their nutritional contribution but also from a sensory perspective.

Protein and polysaccharide mixed systems have been actively studied for at least 50 years as they can be assembled into functional particles or gels. This article reviews the properties of electrostatic gels, a recently discovered particular case of associative protein–polysaccharide mixtures formed through associative electrostatic interaction under appropriate solution conditions (coupled gel). This review highlights the factors influencing gel formation such as protein–polysaccharide ratio, biopolymer structural characteristics, final pH, ionic strength and total solid concentration. For the first time, the functional properties of protein–polysaccharide coupled gels are presented and discussed in relationship to individual protein and polysaccharide hydrogels. One of their outstanding characteristics is their gel water retention. Up to 600 g of water per g of biopolymer may be retained in the electrostatic gel network compared to a protein gel (3–9 g of water per g of protein). Potential applications of the gels are proposed to enable the food and non-food industries to develop new functional products with desirable attributes or new interesting materials to incorporate bioactive molecules.

Recent results showed that solid food disintegration in the stomach may be affected by food texture which was demonstrated to change during digestion. Cheese is complex as, depending on the variety, its composition and texture can be modulated. Cheddar, light Cheddar, Mozzarella and light Mozzarella cheese particles were digested in vitro. Cheese disintegration and nutrients release were studied throughout the oral, gastric and duodenal digestion steps in presence or absence of enzymes. Cheese disintegration was significantly affected by the enzymatic treatment (with or without enzymes). The addition of enzymes allowed to reach 72% of cheese disintegration at the end of the duodenal digestion while it has attained 30% when no enzymes were added. Cheddar cheese disintegration was the highest among cheeses. This phenomenon was related to its initial higher fat content which resulted in a higher fat release during digestion. The disintegration at the end of each digestion step was also correlated to cheese composition (proteolysis and fat) and to textural parameters (hardness, resilience, adhesiveness and chewiness). Light Cheddar and Mozzarella exhibited similar disintegration and nutrients release at the end of the digestion due to a relatively small fat reduction (6%) which had limited effect on cheese texture. This study provides quantitative evidence regarding the impact of cheese textural changes during digestion on cheese disintegration and macronutrients release which may further affect nutrients anabolic response and some physiological functions.