Effects of food processing on in vitro glucose release of high methylester pectin-enriched doughs.

The incidence of type 2 diabetes is linked to consuming processed, high-glycemic foods low in dietary fiber. Soluble dietary fibers are known to improve blood glucose tolerance. This study examined the impact of processing on the in vitro glucose release of fiber-rich, high-glycemic foods. The impact of composition and microstructure on in vitro glucose release and starch digestibility was evaluated in doughs - untreated, baked at 180 °C, and extruded at 150 °C and 180 °C - with partial enrichment of high-methylester pectin. Pectin enrichment decreased starch digestibility, altered the food matrix, and doubled in vitro chyme-viscosity resulting in reduced glucose release in baked (180 °C), and extruded (150 °C) products. Baking or extrusion cooking increased starch digestibility - converting slowly into rapidly available starch and free glucose. Additionally, resistant starch levels were enhanced by up to fivefold. The variations in glucose release originated from a complex interplay between starch digestibility, viscosity, and the food matrix.

Production of Protein Concentrates from Macauba (Acrocomia aculeata and Acrocomia totai) Kernels by Sieve Fractionation.

Macauba palm fruits (Acrocomia aculeata and Acrocomia totai) are emerging as sources of high-quality oils from their pulp and kernels. The protein-rich macauba kernel meal (MKM) left after oil extraction remains undervalued, mainly due to the lack of suitable deoiling parameters and integrated protein recovery methods. Therefore, the present study aimed to produce protein concentrates from MKM using sieve fractionation. The deoiling parameters, comprising pressing, milling, and solvent extraction, were improved in terms of MKM functionality. The combination of hydraulic pressing, milling to 1 mm, and the hexane extraction of A. aculeata kernels resulted in MKM with the highest protein solubility (77.1%), emulsifying activity index (181 m2/g protein), and emulsion stability (149 min). After sieve fractionation (cut size of 62 µm), this meal yielded a protein concentrate with a protein content of 65.6%, representing a 74.1% protein enrichment compared to the initial MKM. This protein concentrate showed a reduced gelling concentration from 8 to 6%, and an increased emulsion stability from 149 to 345 min, in comparison to the MKM before sieving. Therefore, sieve fractionation after improved deoiling allows for the simple, cheap, and environmentally friendly recovery of MKM proteins, highlighting the potential of macauba kernels as a new source of protein.

The Effect of Corn Dextrin on the Rheological, Tribological, and Aroma Release Properties of a Reduced-Fat Model of Processed Cheese Spread.

Low-calorie and low-fat foods have been introduced to the market to fight the increasing incidence of overweightness and obesity. New approaches and high-quality fat replacers may overcome the poor organoleptic properties of such products. A model of processed cheese spread (PCS) was produced as a full-fat version and with three levels of fat reduction (30%, 50%, and 70%). Fat was replaced by water or by corn dextrin (CD), a dietary fiber. Additionally, in the 50% reduced-fat spreads, fat was replaced by various ratios of CD and lactose (100:0, 75:25, 50:50, 25:75, and 0:100). The effect of each formulation was determined by measuring the textural (firmness, stickiness, and spreadability), rheological (flow behavior and oscillating rheology), tribological, and microstructural (cryo-SEM) properties of the samples, as well as the dynamic aroma release of six aroma compounds typically found in cheese. Winter's critical gel theory was a good approach to characterizing PCS with less instrumental effort and costs: the gel strength and interaction factors correlated very well with the spreadability and lubrication properties of the spreads. CD and fat exhibited similar interaction capacities with the aroma compounds, resulting in a similar release pattern. Overall, the properties of the sample with 50% fat replaced by CD were most similar to those of the full-fat sample. Thus, CD is a promising fat replacer in PCS and, most likely, in other dairy-based emulsions.

Characterization of Reduced-Fat Mayonnaise and Comparison of Sensory Perception, Rheological, Tribological, and Textural Analyses.

Reduced-fat products can help to fight obesity and its associated health risks. To develop appealing products, both product-specific fat replacers and suitable analytical methods for the characterization of fat-associated properties are important. The rheology, tribology, texture, and spreadability of a reduced-fat mayonnaise with different concentrations of corn dextrin were analyzed to determine properties such as flow behavior, viscosity, lubricity, firmness, and stickiness. Additionally, a sensory panel analyzed the samples for their mouthfeel (creaminess, firmness, and stickiness). Correlations between the results of the instrumental methods suggested that the analytical effort for the future development of appealing reduced-fat food products can be reduced. In addition, several correlations were identified between the instrumental and the sensory data. Results from tribological measurements correlated with the sensory attribute of stickiness, suggesting that tribometry can complement or constitute an alternative to complex and expensive human sensory tests. Additionally, the use of Stevens' power law showed a high correlation between the Kokini oral shear stress and the sensory attribute of creaminess. The instrumental texture properties (firmness, stickiness) also correlated with the sensory sensation. The identified correlations obtained from comparing different methods may help to estimate the possible applications of new fat replacers and facilitate innovative product development.

Influence of Fat Replacers on the Rheological, Tribological, and Aroma Release Properties of Reduced-Fat Emulsions.

Reduced-fat food products can help manage diet-related health issues, but consumers often link them with poor sensory qualities. Thus, high-quality fat replacers are necessary to develop appealing reduced-fat products. A full-fat model emulsion was reduced in fat by replacing fat with either water, lactose, corn dextrin (CD), inulin, polydextrose, or microparticulated whey protein (MWP) as fat replacers. The effect of fat reduction and replacement, as well as the suitability of different types of fat replacers, were determined by analyzing fat droplet size distribution, composition, rheological and tribological properties, and the dynamic aroma release of six aroma compounds prevalent in cheese and other dairy products. None of the formulations revealed a considerable effect on droplet size distribution. MWP strongly increased the Kokini oral shear stress and viscosity, while CD exhibited similar values to the full-fat emulsion. All four fat replacers improved the lubricity of the reduced-fat samples. Butane-2,3-dione and 3-methylbutanoic acid were less affected by the changes in the formulation than butanoic acid, heptan-2-one, ethyl butanoate, and nonan-2-one. The aroma releases of the emulsions comprising MWP and CD were most similar to that of the full-fat emulsion. Therefore, CD was identified as a promising fat replacer for reduced-fat emulsions.

Peripheral Amino Acid Appearance Is Lower Following Plant Protein Fibre Products, Compared to Whey Protein and Fibre Ingestion, in Healthy Older Adults despite Optimised Amino Acid Profile.

Plant-based proteins are generally characterised by lower Indispensable Amino Acid (IAA) content, digestibility, and anabolic properties, compared to animal-based proteins. However, they are environmentally friendlier, and wider consumption is advocated. Older adults have higher dietary protein needs to prevent sarcopenia, a disease marked by an accelerated loss of muscle mass and function. Given the lower environmental footprint of plant-based proteins and the importance of optimising dietary protein quality among older adults, this paper aims to assess the net peripheral Amino Acid (AA) appearance after ingestion of three different plant protein and fibre (PPF) products, compared to whey protein with added fibre (WPF), in healthy older adults. In a randomised, single-blind, crossover design, nine healthy men and women aged ≥65 years consumed four test meals balanced in AA according to the FAO reference protein for humans, matched for leucine, to optimally stimulate muscle protein synthesis in older adults. A fasted blood sample was drawn at each visit before consuming the test meal, followed by postprandial arterialise blood sampling every 30 min for 3 h. The test meal was composed of a soup containing either WPF or PPF 1-3. The PPF blends comprised pea proteins with varying additional rice, pumpkin, soy, oat, and/or almond protein. PPF product ingestion resulted in a lower maximal increase of postprandial leucine concentration and the sum of branched-chain AA (BCAA) and IAA concentrations, compared to WPF, with no effect on their incremental area under the curve. Plasma methionine and cysteine, and to a lesser extent threonine, appearance were limited after consuming the PPF products, but not WPF. Despite equal leucine doses, the WPF induced greater postprandial insulin concentrations than the PPF products. In conclusion, the postprandial appearance of AA is highly dependent on the protein source in older adults, despite providing equivalent IAA levels and dietary fibre. Coupled with lower insulin concentrations, this could imply less anabolic potential. Further investigation is required to understand the applicability of plant-based proteins in healthy older adults.

Usual Protein Intake Amount and Sources of Nursing Home Residents with (Risk of) Malnutrition and Effects of an Individualized Nutritional Intervention: An enable Study.

Nursing home (NH) residents with (risk of) malnutrition are at particular risk of low protein intake (PI). The aim of the present analysis was (1) to characterize usual PI (total amount/day (d) and meal, sources/d and meal) of NH residents with (risk of) malnutrition and (2) to evaluate the effects of an individualized nutritional intervention on usual PI. Forty residents (75% female, 85 ± 8 years) with (risk of) malnutrition and inadequate dietary intake received 6 weeks of usual care followed by 6 weeks of intervention. During the intervention phase, an additional 29 ± 11 g/d from a protein-energy drink and/or 2 protein creams were offered to compensate for individual energy and/or protein deficiencies. PI was assessed with two 3-day-weighing records in each phase and assigned to 4 meals and 12 sources. During the usual care phase, mean PI was 41 ± 10 g/d. Lunch and dinner contributed 31 ± 11% and 32 ± 9% to daily intake, respectively. Dairy products (median 9 (interquartile range 6-14) g/d), starchy foods (7 (5-10) g/d) and meat/meat products (6 (3-9) g/d) were the main protein sources in usual PI. During the intervention phase, an additional 18 ± 10 g/d were consumed. Daily PI from usual sources did not differ between usual care and intervention phase (41 ± 10 g/d vs. 42 ± 11 g/d, p = 0.434). In conclusion, daily and per meal PI were very low in NH residents with (risk of) malnutrition, highlighting the importance of adequate intervention strategies. An individualized intervention successfully increased PI without affecting protein intake from usual sources.

Effects of Extraction Conditions on Banana Peel Polyphenol Oxidase Activity and Insights into Inactivation Kinetics Using Thermal and Cold Plasma Treatment.

The objective of this work was to characterize banana peel polyphenol oxidase (PPO) and to study the inactivation kinetics during thermal and cold atmospheric pressure plasma treatment. Since varietal differences in enzyme characteristics are a well-known phenomenon, 'Prata' banana peel PPO was characterized, and PPO activity and thermal stability of the peel PPO of the two dessert banana cultivars 'Cavendish' and 'Prata' were compared to identify the cultivar better suited for industrial food applications. A crude extract obtained from the peels of the Brazilian banana variety 'Prata' revealed highest PPO activities (46.0-55.2 nkat/mL) at 30-40 °C in a range of pH 6.0-6.5 after addition of 0.5 g/gsample polyvinylpyrrolidone and 0.5% (v/v) Triton X-100 during extraction. 'Cavendish' PPO activity was four times higher. Banana peel PPO exhibited the highest affinity towards dopamine (KM = 0.94 mM). Thermal inactivation of 'Prata' and 'Cavendish' PPO was achieved at 90 °C after 5 and 15 min, respectively, whereas cold plasma treatment did not decrease PPO activity below 46% of the initial enzyme activity. The inactivation behavior of PPO could successfully be described by a two-fraction model indicating at least two types of isoenzymes with different thermal stability. The overall high thermal stability was mainly attributed to membrane-bound PPO. The results may help to prevent enzymatic browning of banana peels and thereby facilitate their valorization as food ingredients.

Effect of Physicochemical Properties of Carboxymethyl Cellulose on Diffusion of Glucose.

Soluble dietary fibers (SDF) are known to reduce the post-prandial plasma glucose levels. However, the detailed mechanisms of this reduced glucose release in the human gut still remain unclear. The aim of our study was to systematically investigate the effect of different types of SDF on glucose release in an in vitro model as a prerequisite for the selection of fibers suitable for application in humans. Three types of carboxymethyl cellulose (CMC) were used to investigate the correlations between fiber concentration, molecular weight (MW), and viscosity on diffusion of glucose using a side-by-side system. CMC solutions below the coil overlap (c*) influenced the glucose diffusivity only marginally, whereas at concentrations above c* the diffusion of glucose was significantly decreased. Solutions of lower MW exhibited a lower viscosity with lower glucose diffusion compared to solutions with higher MW CMC, attributed to the higher density of the solutions. All CMC solutions showed a systematic positive deviation from Stokes-Einstein behavior indicating a greater rise in viscosity than reduction in diffusion. Therefore, our results pave the way for a new approach for assessing glucose diffusion in solutions comprising dietary fibers and may contribute to further elucidating the mechanisms of post-prandial plasma glucose level reduction.

An Individualised Nutritional Intervention Concept for Nursing Home Residents with or at Risk of Malnutrition: An enable Study.

Dietary intake and requirements in nursing home (NH) residents vary individually, but concepts for individualised interventions are currently lacking. Therefore, we present an individualised modular nutritional intervention concept for NH residents with (risk of) malnutrition and describe its application and acceptability. Three enrichment modules-a sweet and a savoury protein cream (40 g, 125 kcal, 10 g protein) and a protein-energy drink (250 mL, 220 kcal, 22 g protein)-were offered to residents of two German NHs single or in combination in five levels of enrichment from level 0 (no enrichment) to 4 (all enrichment modules) to compensate for individual energy and protein deficiencies. Residents with chewing and/or swallowing difficulties received reshaped instead of usual texture-modified meals. The intervention concept was applied to 55 residents (Mean age of 84 ± 8 years, 76.0% female, 25.5% malnutrition). Despite (risk of) malnutrition, 18.2% received no enrichment (level 0). Level 1 was allocated to 10.9%, level 2 to 27.3%, level 3 to 20.0% and level 4 to 23.6% of the residents. 32.7% received reshaped texture-modified meals (RTMM). Participants consuming RTMM were more often assigned to level 4 than residents receiving usual meals (38.8% vs 16.2%). We proposed and successfully applied an individualised modular nutritional intervention concept to NH residents with (risk of) malnutrition. In the next step, the effects of the concept and its transferability to other NHs need to be demonstrated.

The combined effects of different fat replacers and rennet casein on the properties of reduced-fat processed cheese.

Reduced-fat food products can help to prevent obesity and other diet-related diseases. However, the removal of fat often impairs the sensory and textural properties of foods, leading to low consumer acceptance. In this study, we tested various concentrations of fat replacers (inulin, corn dextrin, polydextrose, and microparticulated whey protein) combined with rennet casein to investigate their effects on the melting behavior, dynamic rheological properties, and hardness of reduced-fat processed cheese. We found that increasing concentrations of inulin and corn dextrin reduced the flowability of cheese in the melting test and can thus be used to inhibit flow during heating. Microparticulated whey protein did not affect flowability but caused an increase in the storage and loss moduli as well as the temperature at gel-sol transition. A similar effect was also shown for rennet casein, whereas inulin and polydextrose had little or no effect on these rheological parameters. Corn dextrin had no effect on the storage and loss moduli, but affected the gel-sol transition temperature. No changes in hardness were detected for any concentration of the fat replacers, but increasing the rennet casein content also increased the hardness of the samples, regardless of the fat replacer used. Our results indicate the different concentrations and combinations of fat replacers and rennet casein that can be included in reduced-fat processed cheese to develop products with specific rheological properties, thus meeting future demand for reduced-fat products with attractive sensory attributes.

Molecularization of Bitter Off-Taste Compounds in Pea-Protein Isolates (Pisum sativum L.).

Activity-guided fractionations, combined with taste dilution analyses (TDA), were performed to locate the key compounds contributing to the bitter off-taste of pea-protein isolates (Pisum sativum L.). Purification of the compounds perceived with the highest sensory impact, followed by 1D/2D-NMR, (LC-)MS/MS, LC-TOF-MS, and MSE experiments, led to the identification of 14 lipids and lipid oxidation products, namely, 9,10,13-trihydroxyoctadec-12-enoic acid, 9,12,13-trihydroxyoctadec-10-enoic acid, 9,10,11-trihydroxyoctadec-12-enoic, 11,12,13-trihydroxyoctadec-9-enoic acid, (10E,12E)-9-hydroxyoctadeca-10,12-dienoic acid, (9Z,11E)-13-hydroxyoctadeca-9,11-dienoic acid, (9E,11E)-13-hydroxyoctadeca-9,11-dienoic acid, 1-linoleoyl glycerol, α-linolenic acid, 2-hydroxypalmitic acid, 2-hydroxyoleic acid, linoleic acid, (9Z,11E)-13-oxooctadeca-9,11-dienoic acid, and octacosa-6,9,19,22-tetraen. Herein, we present the isolation, structure determination, and sensory activity of these molecules. Depending on their structure, the isolated compounds showed human bitter recognition thresholds between 0.06 and 0.99 mmol/L in water.

Differentiation of Adsorptive and Viscous Effects of Dietary Fibres on Bile Acid Release by Means of In Vitro Digestion and Dialysis.

To explain the cholesterol-reducing effects of dietary fibres, one of the major mechanisms proposed is the reduced reabsorption of bile acids in the ileum. The interaction of dietary fibres with bile acids is associated with their viscous or adsorptive effects. Since these fibre characteristics are difficult to investigate in vivo, suitable in vitro methodologies can contribute to understanding the mechanistic principles. We compared the commonly used centrifugal approach with a modified dialysis method using dietary fibre-rich materials from different sources (i.e., barley, citrus, lupin, and potato). Digestion was simulated in vitro with oral, gastric, and small intestinal digestion environments. The chyme was dialysed and released bile acids were analysed by high-performance liquid chromatography. The centrifugation method showed adsorptive effects only for cholestyramine (reference material) and a high-fibre barley product (1.4 µmol taurocholic acid/100 mg dry matter). Alternatively, the dialysis approach showed higher values of bile acid adsorption (2.3 µmol taurocholic acid/100 mg dry matter) for the high-fibre barley product. This indicated an underestimated adsorption when using the centrifugation method. The results also confirmed that the dialysis method can be used to understand the influence of viscosity on bile acid release. This may be due to entrapment of bile acids in the viscous chyme matrix. Further studies on fibre structure and mechanisms responsible for viscous effects are required to understand the formation of entangled networks responsible for the entrapment of the bile acids.

Lipoxygenase activity in different species of sweet lupin (Lupinus L.) seeds and flakes.

Lipoxygenase (LOX)-catalysed degradation of polyunsaturated fatty acids is supposed to be a major cause of undesirable off-flavour development in legumes. In the present study, a photometric LOX assay including adequate sample workup was adapted to lupin seeds, kernels and flakes, respectively. Optimum reaction conditions were at pH 7.5 using a phosphate buffer concentration of 150 mmol l(-1) without the addition of sodium chloride. The LOX activities of different lupin species and varieties were compared. Significant variations among the species and varieties ranging from 50 to 1004 units mg(-1) protein were determined, being significantly lower than soybean LOX activity. Hulling and flaking of the seeds resulted in a 15% increase of LOX activity. In contrast to soy and other legumes, LOX from lupin only converted free fatty acids, whereas trilinolein and ß-carotene were not oxidised. Consequently, according to the established classification, lupin LOX activity may be assigned to the LOX type-1, which, to the best of our knowledge, was demonstrated for the first time.