Rye Endosperm Research Articles

Historical stages of creation of soft winter wheat varieties in NSC «Institute of Agriculture of the National Academy of Sciences»

Aim. Solving the tasks of creating a variety of soft winter wheat at each stage of the historical development of the programs is impossible without an appropriate theoretical generalization of increasing yield, improving the resistance of the best candidate varieties to biotic and abiotic environmental factors, reproducing valuable economic traits and selecting plants with high performance grain quality. Methods. Field, laboratory, mathematical and statistical. Results. At each stage of the research, varieties with higher yield and economic value were created using different methods in the selection process. Selection and hybridization methods are characteristic for the I-II stage. From the III-VI stage, an unconventional method of injecting soft winter wheat grains with the endosperm of winter rye was started, as a result of which the Poliska 70 and Poliska 90 wheat varieties were created. The method of chemical mutagenesis was expanded. Included in the hybridization Wheat-sedge hybrid (PPG). Thanks to PPG, at the VIII stage, the varieties Pam’yati Girka, Spivanka Poliska were created. At the VII stage, ecological research was launched not only in the Polissia zone, but also in the Forest-Steppe zone of Ukraine, and the method of thermal mutagenesis was used. At the VIII-IX stages, Romanivna and Zaotar varieties were created using this method. Pyryatinka, Lubito. With a combination of thermal mutagenesis and hybridization of Osyaina and Zemlerob varieties. The IX (military) stage is characterized by sowing without fertilizers and without the use of insecticides and fungicides. Conclusions. The best varieties of soft winter wheat of the competitive variety test according to yield in the selective crop rotation of the NSC «Institute of Agriculture of the National Academy of Sciences» − Kraevyd, Myrolyubna, Krasunya Poliska, Kesaria Poliska, Efectna, Namysto, Merezhka, Vodogray, Presygna, Spivanka Poliska, Fortsia Poliska, Pyryatinka, Mokosha, Zemlerob, Lubito. On the breeding base Kopylyv proved themselves better − Polysyanka, Vodogray, Romanivna, Namisto, Kraevyd, Prestighna, Rusyava. At the Panfilsk research station – Myrolyubna, Kesaria Poliska, Merezhka, Pamiati Girka, Polysyanka, Kraevyd, Vodogray, Zmelerob. At the Cherkasy research station (the village of Kholodnyanske, Cherkasy district and the village of Drabovo-Boryatynske, Zolotonsky district) Poliska Fortress, Kesaria Poliska, Polysyanka, Kraevyd, Poliska Spivanka.

Exploiting Rye in Wheat Quality Breeding: The Case of Arabinoxylan Content.

Rye (Secale cereale subsp. cereale L.) has long been exploited as a valuable alternative genetic resource in wheat (Triticum aestivum L.) breeding. Indeed, the introgression of rye genetic material led to significant breakthroughs in the improvement of disease and pest resistance of wheat, as well as a few agronomic traits. While such traits remain a high priority in cereal breeding, nutritional aspects of grain crops are coming under the spotlight as consumers become more conscious about their dietary choices and the food industry strives to offer food options that meet their demands. To address this new challenge, wheat breeding can once again turn to rye to look for additional genetic variation. A nutritional aspect that can potentially greatly benefit from the introgression of rye genetic material is the dietary fibre content of flour. In fact, rye is richer in dietary fibre than wheat, especially in terms of arabinoxylan content. Arabinoxylan is a major dietary fibre component in wheat and rye endosperm flours, and it is associated with a variety of health benefits, including normalisation of glycaemic levels and promotion of the gut microbiota. Thus, it is a valuable addition to the human diet, and it can represent a novel target for wheat-rye introgression breeding.

Technological methods for reducing the content of fructan in rye bread

The irritable bowel syndrome (IBS) is a functional disorder of the gastrointestinal tract that may afflict even 12% of the European population. One of the ways to counteract IBS-related ailments is to implement a diet with reduced contents of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs). The prevailing components from the FODMAPs group that may be found in rye bread include fructans. The study was conducted with endosperm and wholemeal rye flours. Dough was prepared from both flours with the use of two methods: I-stage method—with the addition of dry leavening—and II-stage method with the use of a sourdough produced with Lactobacillus plantarum, and all with fermentation times of 90, 120, 150, and 180 min. After baking, bread loaves were subjected to quality and consumer analysis and fructan content determination. The endosperm rye flour used for bread-making revealed better baking properties. Bread made of this flour had a higher loaf volume and received higher scores in the consumer assessment than bread made with wholemeal. Study results conclude that the content of fructans in bread was significantly affected by the dough-making method, and that it was decreased by the use of the sourdough. In contrast, the extended fermentation time of dough failed to reduce the fructan content of the bread.

The role of rye bran acidification and in situ dextran formation on structure and texture of high fibre extrudates

High insoluble dietary fibre content causes challenges with structure and texture in extrusion. This paper focused on studying the structure of extrudate enriched with rye bran modified in different ways. Fermentation of rye bran with dextran-producing Weissella confusa (with 10 g/100 g, 5 g/100 g and 0 g/100 g added sucrose as substrate for dextran production), in situ enzymatic production of dextran in the bran and chemical acidification of bran with lactic acid were compared in extrusion trials. Endosperm rye flour was the base in extrusion, of which 32 g/100 g was substituted for rye bran. Fermentation with dextran production showed similar improvement in extrudate expansion as chemically acidified bran samples (489 and 493%), in comparison with native bran (420%). Similarly, these treatments decreased extrudate hardness and increased crispiness index (CI) (16 N, 0.06 and 14 N, 0.071 respectively) compared to the control (39 N, 0.008). Enzymatically produced dextran did not affect expansion, although it decreased hardness (26 N) and increased CI compared to the control (0.023). Chemical changes in the fermented and acidified rye bran included reduction in insoluble dietary fibre (DF) (19 g/100 g → 17 g/100 g) and increase in soluble DF (5.17 g/100 g → 5.51–7.19 g/100 g), as well as soluble protein (8 g/100 g → 11 g/100 g) content. Lactic acid bacteria fermentation or acidification is therefore a promising method to increase the functionality of rye bran in extrusion.

The effects of whole-grain compared with refined wheat, rice, and rye on the postprandial blood glucose response: a systematic review and meta-analysis of randomized controlled trials

Whole grains are often referred to collectively, despite differences in their composition, physical structure, processing, and potential health benefits. The aim of this study was to compare the postprandial blood glucose response of whole-grain with refined wheat, rice, or rye, while controlling for the food delivery matrix and the processing of the grain (e.g., grinding, germination). Eleven electronic databases were systematically searched to identify studies published up to and including November 2017. Randomized controlled trials comparing the effects of whole-grain wheat, rice, or rye with those of each grain's refined counterpart on postprandial blood glucose area under the curve (AUC) were included. Pooled effect sizes were computed by using the difference in the blood glucose AUC after the consumption of the whole compared with the refined grain. Twenty publications were included, with 10, 14, and 5 strata (or active-control comparisons) on whole-grain wheat, rice, and rye, respectively. The consumption of ground (wholemeal) wheat, compared with white wheat, was not associated with a significant reduction in blood glucose AUC (-6.7 mmol/L ⋅ min; 95% CI: -25.1, 11.7 mmol/L ⋅ min; P=0.477). The consumption of wholemeal rye, compared with endosperm rye, was not associated with a significant reduction in blood glucose AUC (-5.5 mmol/L ⋅ min; 95% CI: -24.8, 13.8 mmol/L ⋅ min; P=0.576). The consumption of intact (whole-grain) rice, compared with white rice, was associated with a significant reduction in blood glucose AUC (-40.5 mmol/L ⋅ min; 95% CI: -59.6, -21.3 mmol/L ⋅ min; P<0.001). Compared with white rice, whole-grain rice significantly attenuates the postprandial blood glucose response. In most of the studies on wheat and rye, the postprandial blood glucose responses to foods formulated with wholemeal compared with refined flours were compared. Whether reductions in the blood glucose AUC can be achieved with whole-grain (as opposed to wholemeal) wheat and rye requires further investigation.

Mastication-induced release of compounds from rye and wheat breads to saliva

Mastication initiates digestion, disintegrating food structure and mixing it with saliva. This study aimed to provide understanding about the first step of bread digestion by exploring release of compounds from bread matrix during mastication. Furthermore, the aim was to identify compound groups that differentiate rye and wheat breads.Fifteen participants masticated whole-meal rye bread, endosperm rye bread, endosperm rye bread with added gluten and wheat bread. The masticated samples were studied with non-targeted LC-MS metabolic profiling.A great number of compounds were released from bread matrices in mastication, and the identified compounds differed largely between bread types. Specifically, rye bread samples were characterized by a greater release of peptides and amino acids, whereas sugars and nucleosides were characteristic for wheat bread. These compounds could potentially act as signal molecules in the alimentary tract and may explain, at least partly, the postprandial physiological effects of the breads identified in earlier studies.

New criteria for the molecular identification of cereal grains associated with archaeological artefacts

The domestication and transmission of cereals is one of the most fundamental components of early farming, but direct evidence of their use in early culinary practices and economies has remained frustratingly elusive. Using analysis of a well-preserved Early Bronze Age wooden container from Switzerland, we propose novel criteria for the identification of cereal residues. Using gas chromatography mass spectrometry (GC-MS), we identified compounds typically associated with plant products, including a series of phenolic lipids (alkylresorcinols) found only at appreciable concentration in wheat and rye bran. The value of these lipids as cereal grain biomarkers were independently corroborated by the presence of macrobotanical remains embedded in the deposit, and wheat and rye endosperm peptides extracted from residue. These findings demonstrate the utility of a lipid-based biomarker for wheat and rye bran and offer a methodological template for future investigations of wider range of archaeological contexts. Alkylresorcinols provide a new tool for residue analysis which can help explore the spread and exploitation of cereal grains, a fundamental component of the advent and spread of farming.

Effects of structural and textural properties of brittle cereal foams on mechanisms of oral breakdown and in vitro starch digestibility

Structural and textural properties as well as the dietary fibre content of solid cereal foams influence the oral breakdown of structure, bolus formation and digestibility. The aim of this study was to investigate how structural differences of solid cereal foams (puffs vs. flakes) affect in vivo chewing and in vitro starch digestion. Four extruded puffs and flakes were produced from endosperm rye flour by extrusion processing without or with 10% rye bran (RB) addition. Extruded puffs and flakes were masticated by fifteen healthy females and the process was monitored using electromyography. Extruded puffs were more porous than flakes (97% vs 35%). The two products were also significantly different (p<0.05) in their structural and textural properties such as expansion, hardness, density and crispiness. A negative correlation was observed between hardness and crispiness index (p<0.05, r=−0.950) and density and porosity (p<0.05, r=−0.964). Addition of 10% RB had a significant effect on structural, textural and mastication properties both for puffs and flakes. Mastication of puffs required less total work than flakes (204 vs. 456%) and they were degraded to smaller particles than flakes during mastication. Irrespectively of the considerable differences in structure, texture and oral disintegration process, no significant (p<0.05) differences were observed between puffs and flakes (86.4 vs. 85.1) in terms of starch hydrolysis index. RB addition increased the hydrolysis index of puffs and flakes to 89.7 and 94.5, respectively, which was probably attributable to the increased number of particles in the bolus.

Bioprocessing of bran with exopolysaccharide producing microorganisms as a tool to improve expansion and textural properties of extruded cereal foams with high dietary fibre content

High dietary fibre levels, especially insoluble that is typical for cereal bran, have been associated with poor structural, textural and sensory properties in extruded products. The effect of fermentation with baker's yeast, fermentation with a mixture of Kazachstania exigua and Lactobacillus brevis with and without added hydrolytic enzymes, as well as with Weissella confusa, on the structural and textural properties of high dietary fibre extrudates (ca. 6–14 g/100 g added fibre) in extrusion was studied. Superior structural and textural extrudate characteristics were achieved by fermentation of bran with dextran producing W. confusa. At 40 g/100 g addition of W. confusa –treated bran (12 g/100 g fibre content) radial expansion was the same as for the pure rye endosperm flour control, while density was 35% lower. Hardness (54.1 → 16.3 N) and crispiness work (4.11 → 0.45 Nmm) were reduced (P < 0.05), while the crispiness index was significantly higher (0.002 → 0.05) than that of the control extrudate. Bioprocessing with mixed fermentation, containing K. exigua and L. brevis, together with hydrolytic enzymes also improved the structural and textural characteristics of the bran in extrusion, while baker's yeast fermentation did not significantly affect these characteristics.

Factors affecting structural properties and in vitro starch digestibility of extruded starchy foams containing bran

Rye bran of two different particle sizes (coarse: 440 μm and fine: 28 μm) were prepared by milling of commercial rye bran. Coarse and fine rye bran was added into a blend of rye endosperm flour and corn starch (70:30) to achieve two bran levels, 15 or 30%, to produce directly puffed extrudates. A co-rotating twin screw extruder was used with a screw speed of 500 rpm, barrel temperature profile: 40-70-75-90-95-110-110 °C and constant feed rate of 67 g/min. Feed moisture content of 17% was used either as in barrel-water feed or as preconditioning. Fine bran addition effectively improved macrostructural properties as compared to coarse bran through increasing expansion by 3.3–11.7% and piece density by 3.8–10.5%. Reduction of bran particle size significantly (P < 0.05) increased crispiness by 66.7–203.3%. Particle size reduction of bran had only minor influences on cell wall thickness, cell area and hydrolysis index of the extrudates. Extrudates made with 30% fine bran at in barrel-water feed provided the crispiest extrudates with lower in vitro hydrolysis index. The results demonstrated that the macrostructural and mechanical properties of extrudates containing rye bran can be improved by reducing bran particle size.

Effects of diverse food processing conditions on the structure and solubility of wheat, barley and rye endosperm dietary fibre

The effects of archetypal food processing conditions (dough formation, baking, extrusion, and cooking/boiling) on dietary fibre structure and extractability from the endosperm flours of rye, hull less barley and wheat are reported. For all flours and processes, the distributions of soluble/insoluble cell wall dietary fibre as well as the chemical composition (arabinoxylan (AX) branching patterns, β-glucan DP3/DP4 (DP = degree of polymerisation) ratios) of solubilised fractions were characterised. The results show that overall the total amounts of AX and β-glucan (BG) were not significantly affected by processing but that there were similar increases in the soluble fibre fraction (20–29%) for baked, extruded, and boiled/cooked processes for each flour, with lower (10–15%) increases for all flours processed into dough. In all cases, solubilised fractions of AX and BG had very similar chemical structures to the starting flour, suggesting that increased solubilisation was not due to specific chemical fractions. Confocal images illustrate loosely-held associations of β-glucan with the cell walls of processed foods in contrast to some of the arabinoxylans which appear more tightly held within the residual cell walls. The similarities in behaviour across the three grains are consistent with mechanical treatments during food preparation resulting in similar extents of disentanglement of physically-constrained AX and BG leading to their partial solubilisation.

Effect of gibberellic acid on α-amylase and ribonuclease activities in rye endosperm after various periods of grain storage

α-Amylase and ribonuclease activities were determined in embryoless rye half-seeds exhibiting different viaibility after various times of storage (2, 5 and 8 years). The half-seeds were incubated for 24, 48, 72 and 96 h with and without GA&lt;sub&gt;3&lt;/sub&gt;. α-Amylase activity in the endosperm of rye grain stored for 2 and 5 years and incubated without the hormone increased considerably, whereas in 8-year grain, practically incapable of germination, it remained almost unchanged. GA3caused a considerable increase of α-amylase activity in all the tested samples. In grain stored for 2 and 5 years the enzyme activity reached its peak under the influence of the hormone earlier than in the control samples. The differences in ribonuclease activity between the particular samples were less pronounced, and the reaction to the hormone much weaker. The results indicate that the reaction of rye endosperm to GA3depends on the physiological properties of the grain.

Dynamics of phosphorus compounds in ripening and germinating cereal grains. Part II. Changes in phosphorus compounds content during germination of wheat, barley and rye grains

The dynamics of phosphorus compounds was investigated in the embryos and endosperm of wheat (Grana), barley (Kosmos) and rye (Pancerne) grain after 2, 4 and 6 days of germination. In germinating grain the phosphorus compounds transformations ran along the way of synthesis in the embryo and of breakdown in the endosperm. The level of phosphorus: inorganic, nucleotides, saccharides esters and their metabolites, lipid, RNA, DNA, phytin free and phytin bound with proteins and proteins rapidly increased in germinating seed embryos. The content of phosphorus free phytin and that bound with proteins, lipids, RNA and DNA in the endosperm rapidly decreased during germination. On the other hand, the saccharides phosphorus and that of their metabolites did not change, and inorganic, nuclotides and proteins-P slightly increased. Germinating rye grains showed a higher rate of synthesis in the embryos and of breakdown in the endosperm of the investigated phosphorus compounds than wheat and barley grains.

Localization of the alkylresorcinols in rye and wheat caryopses

A histological method for detecting of 5-n-alkylresorcinols in grains sections using the staining with Fast Blue B was developed. Taking advantage of that method it was found that alkylresorcinols are localized exclusively in the outer cuticle, but both germs and starchy endosperm of rye and wheat seeds are entirely free of these compounds.

Effects of wheat and rye bread structure on mastication process and bolus properties

Chemical composition, baking process and structure of breads influence their degradation in digestion leading to different postprandial responses. Rye bread has a very different structure as compared to wheat bread, and rye breads are known to induce lower postprandial insulin responses than wheat bread. The aim of this study was to find out potential differences in mastication and initial starch hydrolysis rate of rye and wheat breads. Three rye breads (wholemeal rye, endosperm rye and endosperm rye with gluten) and wheat bread were masticated by fifteen participants and the process was monitored using electromyography. The particle size distribution and initial in vitro starch hydrolysis of the bread boluses were analysed. Specific volume correlated negatively and closed porosity of breads correlated positively with work required for mastication. When compared to wheat bread, wholemeal rye bread required more work for mastication process (p=0.004). Rye breads were degraded to smaller particles than wheat bread during mastication. There was a trend (p=0.098) towards slower in vitro starch hydrolysis rate in rye bread boluses than in wheat bread boluses. The results indicate that the digestion process of rye breads differs from that of wheat bread already in the early phase of digestion. This may be one reason behind the unique postprandial responses reported for rye breads.

Enzymatic modification and particle size reduction of wheat bran improves the mechanical properties and structure of bran-enriched expanded extrudates

The aim of this study was to examine enzymatic modification of wheat bran, performed in a low-moisture process, and the reduction of bran particle size as means of improving the technological performance of wheat bran in expanded extrudates. Modification of bran by hydrolytic enzymes increased the crispiness and decreased the hardness and piece density of extrudates containing wheat bran and endosperm rye flour in 20:80 ratio. These improvements correlated (P < 0.01 or 0.05) with an increased content of water extractable arabinoxylan and decreased water holding capacity of the bran, as well as with increased longitudinal expansion of the extrudates. Furthermore, bran with a fine average particle size (84 μm) produced extrudates with improved mechanical properties and higher radial expansion than coarse bran (particle size 702 μm). The impact of bran particle size was also observed in the cellular structure of the extrudates as differences in cell size and homogeneity. The bran drying method, oven or freeze drying after enzymatic modification, did not have a major impact on the properties of the extrudates. The study showed that the functionality of wheat bran in extrusion can be improved by enzymatic modification using a low-water process and by reduction of bran particle size.

Postprandial differences in the plasma metabolome of healthy Finnish subjects after intake of a sourdough fermented endosperm rye bread versus white wheat bread.

BackgroundThe mechanism behind the lowered postprandial insulin demand observed after rye bread intake compared to wheat bread is unknown. The aim of this study was to use the metabolomics approach to identify potential metabolites related to amino acid metabolism involved in this mechanism.MethodsA sourdough fermented endosperm rye bread (RB) and a standard white wheat bread (WB) as a reference were served in random order to 16 healthy subjects. Test bread portions contained 50 g available carbohydrate. In vitro hydrolysis of starch and protein were performed for both test breads. Blood samples for measuring glucose and insulin concentrations were drawn over 4 h and gastric emptying rate (GER) was measured. Changes in the plasma metabolome were investigated by applying a comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry metabolomics platform (GC×GC-TOF-MS).ResultsPlasma insulin response to RB was lower than to WB at 30 min (P = 0.004), 45 min (P = 0.002) and 60 min (P < 0.001) after bread intake, and plasma glucose response was significantly higher at time point 90 min after RB than WB intake (P = 0.045). The starch hydrolysis rate was higher for RB than WB, contrary to the in vitro protein digestibility. There were no differences in GER between breads. From 255 metabolites identified by the metabolomics platform, 26 showed significant postprandial relative changes after 30 minutes of bread intake (p and q values < 0.05). Among them, there were changes in essential amino acids (phenylalanine, methionine, tyrosine and glutamic acid), metabolites involved in the tricarboxylic acid cycle (alpha-ketoglutaric, pyruvic acid and citric acid) and several organic acids. Interestingly, the levels of two compounds involved in the tryptophan metabolism (picolinic acid, ribitol) significantly changed depending on the different bread intake.ConclusionsA single meal of a low fibre sourdough rye bread producing low postprandial insulin response brings in several changes in plasma amino acids and their metabolites and some of these might have properties beneficial for health.

Coeliac disease as the cause of resistant sideropenic anaemia in children with Down's syndrome: Case report

Coeliac disease (CD) is a permanent intolerance of gluten, i.e., of gliadin and related proteins found in the endosperm of wheat, rye and barley. It is characterized by polygenic predisposition, autoimmune nature, predominantly asymptomatic or atypical clinical course, as well as by high prevalence in patients with Down's syndrome (DS) and some other diseases. We are presenting a girl and two boys, aged 6-7 (x = 6.33) years with DS and CD recognized under the feature of sideropenic anaemia resistant to oral therapy with iron. Beside mental retardation, low stature and the morphological features characteristic of DS, two patients had a congenital heart disease; one ventricular septal defect and the other atrioventricular canal. In two patients, trisomy on the 21st chromosome pair (trisomy 21) was disclosed in all cells, while one had a mosaic karyotype. All three patients had classical laboratory parameters of sideropenic anaemia: blood Hb 77-89 g/l (x = 81.67), HCT 0.26-0.29% (x = 0.28), MCV 69-80 fl (x = 73), MCH 24.3-30 pg (x = 26.77) and serum iron 2-5 micromol/L (x = 4.0). Beside anaemia and in one patient a mild isolated hypertransaminasemia (AST 67 U/l, ALT 62 U/l), other indicators of CD were not registered in any of the children. In addition, in all three patients, we also detected an increased level of antibodies to tissue transglutaminase (atTG) of IgA class (45-88 U/I) so that we performed endoscopic enterobiopsy in order to reliably confirm the diagnosis of CD. In all three patients, the pathohistological finding of the duodenal mucosa specimen showed mild to moderate destructive enteropathy associated with high intraepithelial lymphocyte infiltration, cryptic hyperplasia and lympho-plasmocytic infiltration of the stroma. In all three patients, the treatment with a strict gluten-free diet and iron therapy applied orally for 3-4 months resulted in blood count normalization and the correction of sideropenia. Serum level of the atTG-IgA, repeated after a 12-month diet, was also normal. CD should be taken into consideration in all cases of sideropenic anaemia resistant to iron oral therapy in children with DS.The diagnosis of CD implicates corresponding pathohistological confirmation, while the treatment of sideropenic anaemia and its complications, beside iron preparations, also requires compliance with a gluten-free diet.

Endosperm and whole grain rye breads are characterized by low post-prandial insulin response and a beneficial blood glucose profile

BackgroundRye products have previously been shown to induce comparatively low post-prandial insulin responses; irrespectively of their glycaemic indices (GI). However, the mechanism behind this lowered insulin demand remains unknown. An improved insulin economy might contribute to the benefits seen in epidemiological studies with whole grain diets on metabolic risk factors and weight regulation. The objective of this study was to explore the mechanism for a reduced post-prandial insulin demand with rye products.Methods12 healthy subjects were given flour based rye products made from endosperm, whole grain or bran, produced with different methods (baking, simulated sour-dough baking and boiling) as breakfasts in random order in a cross-over design. White wheat bread (WWB) was used as a reference. Blood glucose, serum insulin, plasma ghrelin and subjective satiety were measured during 180 minutes. To evaluate the course of post-meal glycaemia, a measure of the glycaemic profile (GP) was introduced defined as the duration for the incremental post-prandial blood glucose response divided with the blood glucose incremental peak (min/mM).ResultsThe study shows that whole grain rye breads and endosperm rye products induced significantly (p < 0.05) lower insulinaemic indices (II's) than WWB. Rye bran bread (RBB) produced significantly higher II compared with all the other rye products. Furthermore, the acute insulin response showed better correlations with the GP than with the GI of the products. The endosperm rye bread and the whole grain rye bread with lactic acid induced a significantly higher GP than RBB, WWB, white wheat- and whole grain rye porridge, respectively. A low insulin incremental peak was associated with less severe late post-prandial hypoglycaemia (r = 0.38, p < 0.001), and hypoglycaemia was negatively correlated to subjective satiety at 180 min (r = -0.28, p < 0.05). A low insulin incremental peak was also associated with a milder recovery of plasma ghrelin in the late post-prandial phase (180 min, r = 0.34, p < 0.01).ConclusionOur study shows that endosperm and wholegrain rye products induce low acute insulinaemic responses and improved glycaemic profiles. The results also suggest that the rye products possess beneficial appetite regulating properties. Further studies are needed to identify the unknown property or bioactive component(s) responsible for these beneficial metabolic features of rye.

The factor modifying α-amylase isozyme pattern from rye endosperm is an endogenous α-amylase inhibitor

An endogenous a-amylase inhibitor protein was identified in germinating grains of rye. This protein binds only with the a-AMY-1 group of a-amylase isozymes to modify their PAGE properties. IEF was employed to dissociate the enzyme and inhibitor proteins. Four alleles at the inhibitor locus found to be located on the long am of chromosome 2R and designated Isa-I, were identified. The polymorphisms observed due to a-amylase-inhibitor interactions are explained in terms of allelic variation at a-Amy-I and Isa-I. Polyacrylamide gel electrophoresis PAGE patterns of a-amylase isozymes from germinating grain of rye, Secale cereale, have previously been shown to be modified by a protein encoded at a single locus with two codominant alleles designated MA and ME (MASOX? 1987; MASOJC and PRZYBECKJ 1988). Allelic forms of this protein were confirmed by observation of isoelectric focussing IEF gels, where they were apparent as single bands of PIS 6.5 (MA) and In barley, Hordeum vulgare, a similar protein has been observed to modify IEF a-amylase patterns and inhibit the activity of group I1 (malt or high PI)