Emulsifying properties of hemp proteins: Effect of isolation technique

peer-reviewedHemp protein was isolated from hemp seed meal using two different isolation procedures: alkali extraction/isoelectric precipitation (HPI) and micellization (HMI). The ability of these proteins to form and stabilize 10% (w/w) sunflower oil-in-water emulsions (at pH = 3.0) was studied at three different concentrations, 0.25, 0.75 and 1.5% (w/w), by monitoring emulsion droplet size distribution, microstructural and morphological properties, rheological behaviour and stability against flocculation, coalescence and creaming. In addition, hemp proteins were analysed for water solubility, denaturation degree and surface/interfacial activity. HMI protein, which was found to be less denatured after isolation, exhibited higher solubility and slightly higher surface/interfacial activity than HPI protein. HMI emulsions possessed a smaller volume mean droplet diameter (d4,3 = 1.92–3.42 μm in 2% SDS) than HPI emulsions (d4,3 = 2.25–15.77 μm in 2% SDS). While HMI stabilized emulsions were characterized with individual droplets covered by protein film, both confocal laser scanning microscopy and flocculation indices indicated occurrence of bridging flocculation in HPI stabilized emulsions. Protein aggregation, which induced flocculation of the droplets, contributed to higher apparent viscosity of HPI stabilized emulsions compared to HMI stabilized emulsions. Interestingly, emulsions stabilized with 1.5% (w/w) HPI exhibited much better creaming and coalescence stability than other emulsions due to the formation of a weak transient network of floccules and higher continuous phase viscosity which both suppressed the movement of the droplets

Functional characteristics of vegetablefat/maltodextrin gel blends as a component for low calorie confectionery fat fillings

Masna punjenja predstavljaju grupu proizvoda koje se koriste u konditorskoj i pekarskoj industriji. Kako ona najčešće sadrže između 30-40% masti, teži se dobijanju formulacija sa redukovanim sadržajem masti. To se može postići zamenom dela masne faze uz upotrebu zamenjivača masti, najčešće hidrokoloida koji imaju osobine slične osobinama zamenjene masti. Maltodekstrini i njihovi geli mogu se koristiti kao zamenjivači masti. Oni predstavljaju produkte hidrolize skroba koji su rastvorljivi u vodi, mogu da poseduju osobine formiranja gela, imaju slične mazive osobine kao i masti i blagi i neutralni ukus. U ovom radu ispitivane su reološke osobine različitih maltodekstrina kao i smeša namenske biljne masti i rastovora/gela maltodekstrina u odnosu 9:1. Na osnovu dobijenih rezultata utvrđeno je da su od svih ispitivanih komercijalnih maltodekstrina, maltodekstrini 01970 i N-Lite D sa namenskom biljnom masti davali stabilne sisteme. Stoga su maltodekstrini 01970 i N-Lite D korišćeni za dalja istraživanja. Namenska biljna mast zamenjivana je sa 15 i 20% gelima maltodekstrina 01970 i N-lite D u tri različita odnosa: 16,7% gela maltodekstrina i 83,3% namenske biljne masti; 33,3% gela maltodekstrina i 66,7% namenske biljne masti i 50% gela maltodekstrina i 50% namenske biljne masti. Određivane su reološke osobine metodom histerezisnog postupka, viskoelastične osobine, kao i teksturne osobine pripremanih smeša. Dobijeni rezultati su ukazivali da prisustvo maltodekstrinskih gela u smeši sa namenskom biljnom masti utiče na pad tiksotropnosti i čvrstoće i povećanje prividnog viskoziteta i viskoelastičnosti ispitivanih sistema. Sve smeše namenske biljne masti i gela maltodekstrina služile su kao komponenta masne faze za pripremu masnih punjenja sa smanjenim sadržajem masti. Povećanjem zamene dela masne faze maltodekstrinskim gelima u masnim punjenjima uzrokovalo je povećanje tiksotropnosti i čvrstoće kao i promenu boje krajnjeg proizvoda. Na osnovu senzorske ocene sprovedene od strane iskusnog senzorskog panela i na osnovu testa prihvatljivosti od strane netreniranih potrošača, najbolje ocenjena masna punjenja bila su ona kod kojih je 5% masti zamenjeno maltodekstrinskim gelima. Međutim, na osnovu rezultata testa prihvatljivosti uočeno je da su i sistemi sa 15% zamene masti bili senzorski prihvatljivi. Takođe je i na osnovu rezultata sprovedenog upitnika na uzorku od 250 ispitanika utvrđeno da su potrošači (64,4%) zainteresovani za konzumiranje konditorskih proizvoda sa smanjenim sadržajem masti.Confectionery fat fillings are products used in confectionery and baking industry. They contain approximately 30-40% of fat. Due to the high fat content, fat fillings have considerable high caloric value. Therefore, there is a trend to decrease fat content in fat filling formulation. That can be achieved by replacing the portion of the fat phase with fat replacers, most often with hydrocolloids having characteristics which tend to mimic properties of replaced fat. Maltodextrins and their gels can be used as potential fat replacers. Maltodextrins represent starch hydrolysis products soluble in water. Also they posses gel forming ability, spreading ability similar to fats, and bland and non sweet taste. Rheological properties of different types of maltodextrins were examined. Also, blends prepared with 90 % of vegetable fat and 10% of maltodextrin solution/gels were rheologically characterised. According to obtained results, it was found that among all tested commercial maltodextrins, 01970 and N-Lite D built stable systems. Therefore, they were used in further measurements. Vegetable fat was partially replaced by 15 and 20% of 01970 and N-Lite D maltodextrin gels in three different ratios (16.66%, 33.33% and 50% respectively). Steady shear, dynamic oscillatory measurements as well as textural measurements were performed. The obtained results indicated that the presence of maltodextrin gels in blends with vegetable fat influenced the decrease of thixotropy and hardness and increase of viscosity and viscoelasticity of the tested systems. All maltodextrin gel/vegetable fat blends were further used for preparation of confectionery fat fillings. The increase in the amount of fat reduction resulted in the increase of thixotropy and hardness and change in colour of the final product. According to sensory analysis performed by trained sensory panel as well as by measurement of product acceptance–preference performed by untrained panellists (consumers), fat filling with 5% fat reduction had the highest scores. However, according to product acceptance–preference measurements it was estimated that the final product with 15% fat reduction was also sensory acceptable. The results of survey performed on 250 participants showed that consumers (64.4%) were interested in consuming low fat confectionery produc

Evaluation of the Possibility to Replace Conventional Rheological Wheat Flour Quality Control Instruments with the New Measurement Tool – Mixolab

Because of the belief that the rheological properties of wheat fl our and dough are related to the flour quality and its processing characteristics, they are of great importance in the baking and milling industries. The Farinograph, Extensograph, Amylograph and Alveograph tests are the most common empirical tests used for assessing rheological properties of wheat dough. Recently, new rheological tool for wheat fl our characterization, called Mixolab, has been developed. The advantage of using Mixolab is that one can measure protein and starch characteristics in a single test. The objective of this study was to determine the relationships between Mixolab parameters and parameters obtained using Farinograph and Amylograph among flour samples of different technological quality. Mixolab water absorption value was significantly correlated to Farinograph water absorption value (r = 0.9816) as well as Mixolab dough formation time value (time for C1) to dough development time obtained using Farinograph (r = 0.9668), while the values which indicate dough stability have not expressed so high correlation (r = 0.7484). In addition, difference between the values of maximum torque (C1) and torque at the end of the first period of constant temperature (T= 30°C) obtained by Mixolab expressed good correlation with the Farinograph degree of softening (r = 0.8504). A significant correlation coefficient (r = 0.8812) was determined between the Amylograph peak viscosity parameter and C3 value which is an indication of starch gelatinization

Spontaneously fermented ancient wheat sourdoughs in breadmaking: Impact of flour quality on sourdough and bread physico-chemical properties

In this study changes during fermentation of spontaneously fermented modern and ancient (spelt, emmer, and khorasan) wheat sourdoughs and their feasibility to act as leavening agents in breadmaking were evaluated. During 6 h of fermentation, sourdough was characterized for lactic acid bacteria and yeasts counts, pH, total titratable acidity (TTA), proteolytic activity, rheological and electrophoretic profiles. The effects of 25 and 50 g/100g sourdough addition on physico-chemical and sensory properties of refined wheat flour bread were also investigated. Although in all sourdoughs a pH drop, increase in proteolytic activity, gliadin and glutenin degradation with fermentation were recorded, due to different flour composition and microbial activity, tested sourdoughs significantly differed in rheological properties and breadmaking quality. Wheat sourdough being characterized by the highest acidification, increase in proteolytic activity, and the most extensive hydrolysis of gliadins, resulted in bread with the lowest specific volume and hardest crumb texture. Emmer sourdough, having the highest TTA, ash and wet gluten content, exhibited the highest extensibility, the least pronounced changes in proteolytic activity and the electrophoretic pattern which produced bread with the highest volume and softest texture. In general, ancient wheat varieties have shown great potential in sourdough breadmaking in comparison to modern wheat

Nutritivna, funkcionalna i senzorska svojstva bezglutenskih krekera pripremljenih od brašna slanutka i uljne pogače tikve golice

Research background. Despite the growing trend of the gluten-free market and the presence of a wide range of gluten-free products, there are still some shortcomings in nutritional and sensory quality of these products. The commercially available gluten-free products are characterised as products of inferior nutritional quality, particularly in terms of protein and dietary fibre content and with high glycaemic index. On the other hand, from a sensory point of view, gluten-free products usually have inappropriate textural and mechanical properties, poor mouthfeel and flavour. This is a consequence of the limiting choice of raw materials that mainly possess large amount of carbohydrate components. Experimental approach. Chickpea flour and two types of pumpkin seed press cake flour (virgin and cold pressed), at two substitution mass fractions (20 and 35%), were blended to produce gluten-free crackers without the presence of conventional gluten-free starch-rich ingredients. This study aims to investigate the effect of these non-conventional flours on nutritional and physicochemical properties, sensory acceptability, antioxidant activity and glycaemic index of crackers. Results and conclusions. All produced crackers can bear nutritional claims ’high fibre’, ’source of protein’ and ’source of minerals’. Replacing chickpea flour with pumpkin seed press cake flour increased protein and total phenolic content and enhanced antioxidant activity. The selected combination of raw materials allows the production of gluten-free crackers with a moderate glycaemic index. Besides nutrient content, the addition of cold-pressed flour increased overall sensory acceptability, noticeably improving taste and flavour scores compared to the control and crackers with virgin pumpkin seed flour. Novelty and scientific contribution. To the best of our knowledge, there is no study investigating the use of chickpea and pumpkin seed press cake flour blend without using conventional gluten-free flour and starch. The used non-conventional flour represents complementary raw materials in terms of protein quality and valuable alternatives to produce nutrient-rich, health-promoting gluten-free crackers with reduced glycaemic response and acceptable sensory properties.Pozadina istraživanja. Usprkos rastućoj potražnji za bezglutenskim proizvodima i širokoj paleti ovih proizvoda dostupnih na tržištu, i dalje postoje određeni nedostaci u njihovoj nutritivnoj i senzorskoj kakvoći. Komercijalno dostupni bezglutenski proizvodi okarakterizirani su kao proizvodi slabije nutritivne vrijednosti, naročito u pogledu sadržaja proteina i dijetetskih vlakana te visokog glikemijskog indeksa. S druge strane, s gledišta senzorske kakvoće, ovi proizvodi obično nemaju odgovarajuća teksturna i mehanička svojstva te zadovoljavajući okus i aromu, što je posljedica ograničenog izbora sirovina, u kojima prevladava ugljikohidratna komponenta. Eksperimentalni pristup. Brašno slanutka pomiješano je s brašnom uljne pogače tikve golice preostale nakon proizvodnje djevičanskog ili hladno prešanog ulja u dva udjela (20 i 35 %) i upotrijebljeno kao sirovina za proizvodnju bezglutenskih krekera bez uobičajenih bezglutenskih sastojaka bogatih škrobom. Svrha je istraživanja bila utvrditi utjecaj ovih nekonvencionalnih vrsta brašna na nutritivna i fizikalno-kemijska svojstva, senzorsku prihvatljivost, antioksidacijsku aktivnost i glikemijski indeks krekera. Rezultati i zaključci. Proizvedeni bezglutenski krekeri mogu biti označeni nutritivnim deklaracijama kao što su \u27bogati vlaknima\u27, \u27izvor proteina\u27 i \u27izvor minerala\u27. Zamjenom dijela brašna slanutka brašnom uljne pogače tikve golice preostale nakon proizvodnje djevičanskog i hladno prešanog ulja povećao se udjel proteina i ukupnih fenola te poboljšala antioksidacijska aktivnost krekera. Odabrana kombinacija sirovina omogućila je proizvodnju bezglutenskih krekera umjerenog glikemijskog indeksa. Osim što je poboljšalo nutritivna svojstva, brašno pogače preostale nakon proizvodnje hladno prešanog ulja tikve golice povećalo je ukupnu senzorsku prihvatljivost krekera, znatno poboljšavajući okus i aromu u usporedbi s kontrolnim uzorkom i krekerima s dodatkom brašna pogače preostale nakon proizvodnje djevičanskog ulja. Novina i znanstveni doprinos. Prema našim spoznajama, u literaturi nisu dostupna istraživanja uporabe brašna slanutka i uljne pogače tikve golice bez uobičajenog dodatka bezglutenskog brašna i škroba. Upotrijebljeni nekonvencionalni sastojci, osim što su komplementarni u smislu kakvoće proteina, predstavljaju vrijedne alternative za proizvodnju nutritivno bogatih bezglutenskih krekera s povoljnim učinkom na zdravlje, smanjenim glikemijskim odgovorom i prihvatljivim senzorskim svojstvima

Characterization of extra-hard cheese produced from donkeys’ and caprine milk mixture

International audienceAbstractCheese cannot be produced solely from equine or donkeys’ milk, because of the unique physico-chemical properties of these milks. The purpose of this study was to characterize a novel dairy product, cheese produced from donkeys’ and caprine milk mixture (60:40% v/v), regarding its chemical, microbiological, textural and sensory properties. Fully ripened cheese was classified as a high-fat, extra-hard cheese, with high sodium (29.97 g.kg−1), magnesium (3.07 g.kg−1) and potassium (4.70 g.kg−1) content. The characterization by lab-on-a-chip electrophoresis revealed lysozyme, α-lactalbumin, immunoglobulins and casein fractions. Palmitic (C16:0) and oleic fatty acids (C18:2 n9-cis) with 25.11 and 24.70%, respectively, were found at the highest concentrations. The medium-chain fatty acids account 18.21% of the total fatty acid content in analysed cheese samples. Escherichia coli, Salmonella spp., Enterobacteriaceae, coagulase-positive staphylococci, Listeria monocytogenes, Bacillus cereus, Clostridium perfringens as well as moulds were under the limit of detection in all analysed samples. After 6 months of cheese ripening (0.94 aw, pH 4.71), total bacterial count, the counts of lactic acid bacteria and yeasts were 6.34 ± 0.03, 4.80 ± 0.10 and 5.81 ± 0.11 log CFU.g−1, respectively. The texture of mature cheese was moderately hard and crumbly. The cheese was described as very salty with strong pronounced creamy, fatty and acidic taste. The characterized donkey/caprine cheese could position this type of cheese as a high-quality functional product, thus having a potential impact on the market

Rheology as a tool to predict the effect of different biotic and abiotic factors on the quality of cereals and pseudocereals

Cereals represent a staple food for a majority of the world’s population and play an important role in food security and nutrition. They are the most produced crops in the world (2777 million tons in 2020), with maize, wheat, and rice comprising more than 80% of total cereal production (FAOSTAT, 2021). The distribution of cereal production around the world depends on various factors (environmental, cultural, political, and economic), among which temperature and water availability have a major impact on crop growth in a given region (Awika, 2011). Maize is the mostly produced cereal crop in the world with over 1162 million tons produced in 2020. The United States of America is the largest producer of maize, accounting for 30% of world production in 2020, followed by China at 22.7% and Brazil at 8.8%. World wheat production in 2020 reached 761 million tons. China and India are the world’s largest producers of wheat, producing approximately 31% of world wheat in 2020, followed by the Russian Federation (9.7%) and the United States (6.8%). World rice production stood at 757 million tons in 2020. Asia is the world’s largest producer of rice, producing about 90% of world rice, with China and India accounting for 57% of world rice production in 2020 (FAOSTAT, 2021). In regions where the main problem is frequent droughts, like in some parts of Africa and India, drought-tolerant crops, such as sorghum and millet, are commonly grown. On the contrary, barley is mostly produced in Northern Europe, northern parts of the United States of America and Canada being more tolerant to cold climates

Technological quality of wheat infested with Rhyzopertha Dominica F. (Coleoptera: Bostrichidae)

Due to its negative impact on the yield and quality of stored grains, the aim of this research was to study the influence of Rhyzopertha dominica F. on rheological properties of wheat flour obtained from grains infested by examined pest. A rheological laboratory device - Mixolab was employed in order to simulate the production process of bread (from the beginning of dough mixing until the end of bread baking). Wet gluten and gluten index, as significant flour quality parameters, were also determined. The flour of wheat varieties Planeta and Kruna was used in these experiments. The samples of both varieties infested with R. dominica (infested samples) were characterized and compared to their uninfested counterparts (control samples). Infested samples expressed a lower gluten index content, greater weakening of the gluten network upon mixing and heating, as well as lower starch gelatinization viscosity in comparison to control samples. Changes in the gluten index value were more pronounced in Planeta variety which was characterized with a higher degree of infestation. Determined changes in rheological properties of infested wheat were mainly dependent on a degree of infestation. However, a varietal dependency on the intensity of changes in technological quality cannot be neglected.Zbog negativnog uticaja na prinos i kvalitet uskladištenog žita, cilj istraživanja je proučavanje uticaja Rhyzoperta dominica F. na reološke osobine pšeničnog brašna dobijenog od zrna infestiranog ispitivanom štetočinom. Za simulaciju proizvodnje hleba (od zamesa do krajnjeg proizvoda – hleba) korišćen je reološki laboratorijski uređaj – Mixolab. Takođe, određen je i sadržaj vlažnog glutena i gluten indeks koji su značajni parametri kvaliteta brašna. U eksperimentu je korišćeno brašno sorti pšenice Planeta i Kruna. Ispitani su uzorci obe sorte infestiranih sa R. dominica (infestirani uzorci) i upoređeni sa odgovarajućim neinfestiranim uzorcima (kontrola). U poređenju sa kontrolnim uzorcima, infestirani uzorci pokazali su manji sadržaj glutena, veće slabljenje glutenske mreže prilikom mešenja i zagrevanja, kao i manji viskozitet i želatinizaciju skroba. Promene u vrednosti gluten indeksa bile su izraženije kod sorte Planeta kod koje je utvrđen veći procenat infestacije.Utvrđene promene u reološkim osobinama infestirane pšenice zavisile su, prvenstveno, od stepena infestacije pšenice. Međutim, intenzitet promena tehnološkog kvaliteta uslovljen je i uticajem sorte, koji ne može biti zanemaren

Effect of Sourdough and Whey Protein Addition on the Technological and Nutritive Characteristics of Sponge Cake

Whey protein and sourdough ferment were used in different combinations to prepare functional sponge cakes, and their mutual influence on batter rheological behaviour as well as product physico–chemical, textural, colour and sensory properties were evaluated. All samples containing whey protein concentrate could bear the nutrition claim ‘a source of protein’. The substitution of wheat flour with whey protein significantly influenced batter viscoelastic behaviour, lowered cake-specific volume, increased product hardness, chewiness, gumminess, and browning index and modified its sensory characteristics. The incorporation of sourdough in protein-enriched sponge cakes improved product-specific volume and appearance compared to a protein-containing sample without sourdough. Although sourdough addition has less of a deteriorating effect on sponge cake rheological and textural properties, when combined with whey protein, it led to a significant reduction in batter elasticity and an increase in product hardness. It was also shown that spontaneously fermented sourdough cannot act as the only leavening agent in sponge cake production. In general, the results of this study have shown that sourdough addition can contribute to improvement in protein-enriched sponge cake quality and that further investigations are necessary in terms of different sourdough and flour type incorporation to minimize the negative effects of protein addition