Recovery, Isolation, and Characterization of Food Proteins

One of the greatest challenges currently facing our society is combating climate change [...

In vitro-study of antioxidant extracts from Garcinia mangostana pericarp and Riesling grape pomace: A contribution to by-products valorization as cosmetic ingredients

The objective of the present study was to compare extracts from two different plant sources regarding their suitability as antioxidant cosmetic ingredients. Both, Garcinia mangostana pericarp, in Europe being widely considered as the non-edible part of a 'superfruit', and Riesling grape pomace accruing from vinification, represent important by-products from food processing. Mixtures of ethanol and water in different ratios were used for the preparation of polyphenol containing extracts. Antioxidant properties of the extracts were determined using well-established in vitro assays (Folin-Ciocalteu, ORAC, DPPH, and ABTS), and skin penetration was investigated by Franz-type diffusion experiments with porcine skin. Extraction of polyphenols was most effective using an equimolar ratio of ethanol and water for both raw materials. Absolute polyphenol contents of mangosteen pericarp extract (65360.71 +/- 1168.51 mg/kg DM) were higher than for grape pomace extract (18085.70 +/- 411.50 mg/kg DM). However, Folin-Ciocalteu reducing capacities as well as in vitro antiradical activities did not adequately correspond to quantitative polyphenol estimations, as grape pomace extract showed relatively high antiradical capacities. When applied to pig skin, polyphenols from grape pomace extract were detected in low concentrations in the dermis as well as in the transdermal receptor fluid. In contrast, mangosteen pericarp xanthones were almost completely recovered with highest amounts detected in the dermis. In conclusion, both raw materials revealed potential as antioxidant ingredients for cosmetic formulations

Contribution of S. xylosus and L. sakei ssp. carnosus Fermentation to the Aroma of Lupin Protein Isolates

Aroma-active compounds of lupin protein isolate and lupin protein isolate fermented with Staphylococcus xylosus and Lactobacillus sakei ssp. carnosus were investigated. The changes in aroma-active compounds were determined by application of aroma extract dilution analysis in combination with gas chromatography-mass spectrometry/olfactometry for identification, and by stable isotope dilution assays for quantification. A total of 30 aroma-active compounds for non-fermented and fermented samples were identified. The aroma profile of LPI fermented with Lactobacillus sakei ssp. carnosus was characterized as roasty and popcorn-like. Staphylococcus xylosus generated cheesy impressions, being in line with the fact that the main aroma compounds acetic acid, butanoic acid, and 2/3-methylbutanoic acid could be identified. Quantification of butanoic acid further confirmed these findings with the highest concentration of 140 mg/kg for LPI fermented with Staphylococcus xylosus. Our study provides insights into how fermentation utilizing different fermentative microbial strains, namely Staphylococcus xylosus and Lactobacillus sakei ssp. carnosus alters the aroma profile of lupin protein isolates. This demonstrates the potential of shaping fermented protein-based foods via targeted microbiological refinement

Innovative Nahrungsmittel. Neue Aufbereitungsverfahren für pflanzliche Rohstoffe führen zu gesunden Alternativen zu herkömmlichen Lebensmitteln und Proteinquellen

Der bis Mitte des Jahrhunderts erwartete Anstieg der Weltbevölkerung auf über 9,5 Milliarden Menschen und der zunehmende Verzehr tierischer Lebensmittel sind eine der größten globalen Herausforderung zur Sicherung der Versorgung der Menschheit. Die Nutzung neuer pflanzlicher Proteinzutaten anstelle von tierischen Eiweißpräparaten kann ein wichtiger Teil der Lösung sein, da die Produktion tierischer Eiweiße rund fünfmal so viel Fläche benötigt wie die Gewinnung von Pflanzenproteinen. Der folgende Beitrag gibt einen Überblick über den Stand der Technik der Gewinnung, Verarbeitung und Applikation pflanzlicher Proteine in der europäischen Lebensmittelindustrie. Dabei werden neben den Chancen und Vorteilen auch bisherige Schwächen pflanzlicher Proteine vorgestellt und Strategien zur Optimierung aufgezeigt. Weiterhin wird über aktuelle Ergebnisse eines Projekts der Fraunhofer-Zukunftsstiftung berichtet, in dessen Rahmen neue Verfahren zur Reduktion des allergenen Potenzials pflanzlicher Proteine entwickelt wurden. Technische Ansätze zur Optimierung von Geschmack, Textur und Mundgefühl pflanzlicher Lebensmittel und Beispiele zur erfolgreichen Umsetzung der Forschungsergebnisse durch Fraunhofer-Ausgründungen schließen den Beitrag ab

Mechanisms of Interactions between Bile Acids and Plant Compounds—A Review

Plant compounds are described to interact with bile acids during small intestinal digestion. This review will summarise mechanisms of interaction between bile acids and plant compounds, challenges in in vivo and in vitro analyses, and possible consequences on health. The main mechanisms of interaction assume that increased viscosity during digestion results in reduced micellar mobility of bile acids, or that bile acids and plant compounds are associated or complexed at the molecular level. Increasing viscosity during digestion due to specific dietary fibres is considered a central reason for bile acid retention. Furthermore, hydrophobic interactions are proposed to contribute to bile acid retention in the small intestine. Although frequently hypothesised, no mechanism of permanent binding of bile acids by dietary fibres or indigestible protein fractions has yet been demonstrated. Otherwise, various polyphenolic structures were recently associated with reduced micellar solubility and modification of steroid and bile acid excretion but underlying molecular mechanisms of interaction are not yet fully understood. Therefore, future research activities need to consider the complex composition and cell-wall structures as influenced by processing when investigating bile acid interactions. Furthermore, influences of bile acid interactions on gut microbiota need to be addressed to clarify their role in bile acid metabolism

Technofunctional and Sensory Properties of Fermented Lupin Protein Isolates

Lupin protein isolate was fermented with eight different microorganisms to evaluate the influence on sensory profile, techno-functional properties and protein integrity. All investigated microorganisms were able to grow in lupin protein isolate. The results showed that the foaming activity in the range of 1646–1703% and the emulsifying capacity in the range of 347–595 mL of the fermented lupin protein isolates were similar to those of the unfermented ones. Protein solubility at pH 4 showed no significant changes compared to unfermented lupin protein isolate, whereas the solubility at pH 7 decreased significantly from 63.59% for lupin protein isolate to solubilities lower than 42.35% for fermented lupin protein isolate. Fermentation with all microorganisms showed the tendency to decrease bitterness from 2.3 for lupin protein isolate (LPI) to 1.0–2.0 for the fermented ones. The most promising microorganisms for the improvement of the sensory properties of lupin protein isolates were Lactobacillus brevis as it reduced the intensity of characteristic aroma impression (pea-like, green bell pepper-like) from 4.5 to 1.0. The SDS-PAGE results showed the fermentation treatment appeared not to be sufficiently effective to destruct the protein integrity and thus, deplete the allergen potential of lupin proteins. Fermentation allows the development of food ingredients with good functional properties in foam formation and emulsifying capacity, with a well-balanced aroma and taste profile

Factors influencing crystallization of erythritol in aqueous solutions: A preliminary study

Erythritol - a new zero caloric sweetener - shows high potential for developing new sugar reduced or sugar free food formulations. Since the crystallization behavior of erythritol was not investigated so far, this study focused on factors influencing erythritol crystallization in aqueous solutions using a simple gravimetric method. The general features of the course of crystallization are a linear increase until a period of 2.5 h of storage followed by a decelerating phase and a phase which represents equilibrium. Additionally, different influencing factors (supersaturation level, storage temperature, storage period and cooling rate) on the crystallization process of erythritol were investigated. It was shown that crystallization value increased with increasing supersaturation level and the progress of crystallization was almost linear from the initial induction period until equilibrium. Therefore, a first-order kinetic for erythritol crystallization was proposed, because only supersaturation level correlated to the erythritol concentration in the solution influenced the course of crystallization. Calculated crystallization rate constants increased considerably with increasing supersaturation levels. Furthermore, at the same supersaturation levels crystallization of erythritol was independent from the storage temperature. Cooling rate influenced only crystal shapes and sizes, but not the crystallization values

Effect of enzyme-assisted hydrolysis on protein pattern, technofunctional, and sensory properties of lupin protein isolates using enzyme combinations

The modification of lupin protein isolates (LPI) by means of enzymatic hydrolysis (Lupinus angustifolius cultivar Boregine) was performed with four enzyme preparations (Alcalase 2.4 L, Papain, Corolase 7089, and Neutrase 0.8 L) in a one‐ and two‐step process to determine the efficacy for the destruction of major IgE‐reactive polypeptides and the evaluation of the technofunctional and sensory properties of lupin protein hydrolysates. Combinations of Alcalase 2.4 L and Papain were most effective in the degradation of polypeptides in L. angustifolius as measured by sodium dodecylsulfate–polyacrylamide gel electrophoresis. The enzymatic hydrolysis of the LPI increased their technofunctional properties such as protein solubility, foam activity, and emulsifying capacity almost independently of the enzyme preparation used. The sensory results showed a significant increase in bitterness from 1.9 for LPI to 5.7 for the combination of Alcalase 2.4 L and Papain in one‐step process. The aroma attributes of the hydrolysates were very similar to untreated LPI. The results of this study show the possibility of enzymatic hydrolysis of LPI to destroy the major IgE‐reactive polypeptides that increase the technofunctional properties of the isolates and thus their use in human nutrition as food ingredients

Characterisation and quantification of xanthones from the aril and pericarp of mangosteens (Garcinia mangostana L.) and a mangosteen containing functional beverage by HPLC-DAD-MS n

Attention on mangosteen fruits as an ingredient of functional products is growing, particularly due to their rich content of xanthones. Whereas mangosteen products containing puree from the entire fruit of Garcinia mangostana L. are considered as novel food in the European Union, such products are widely used in the US due to their high antioxidant potential and traditional consumption in their countries of origin. With special emphasise on the xanthone profile and content, mangosteen pericarp, aril segments and a functional beverage made from whole mangosteens were compared. The fruit parts and the product showed a consistent pattern composed of mainly 7 xanthones, which could be unambiguously identified by LC-MS. Based on collision-induced dissociation experiments, fragmentation pathways of xanthones were suggested. The quantification of 7 derivatives contained in the arils, the pericarp and the functional beverage allowed an estimation of the amounts of bioactives wh ich are ingested by the consumption of fresh mangosteen fruits and beverages produced thereof. Total xanthone content of the pericarp was the highest, revealing its potential as functional ingredient - followed by the aril segments and the functional beverage. It has been shown, that the content of bioactive xanthones in 90 mL of the beverage (i.e. the recommended daily dose) corresponds to about 0.9 g of pericarp and the aril segments (30 g) of a single mangosteen. Since residual parts of pericarp are always ingested after usual peeling of the fruit, xanthone concentrations exceeding those of the nutritional beverage have been ingested, thus allowing to establish a safe history of use

Retention of Primary Bile Acids by Lupin Cell Wall Polysaccharides Under In Vitro Digestion Conditions

Interference of dietary fibres with the enterohepatic circulation of bile acids is proposed as a mechanism for lowering cholesterol. We investigated how lupin hull and cotyledon dietary fibres interact with primary bile acids using an in vitro model under simulated upper gastrointestinal conditions. Cell wall polysaccharides were isolated and extracted to separate pectin-like, hemicellulosic, and lignocellulosic structures. Lupin hull consisted mainly of structural components rich in cellulose. The viscosity of the in vitro digesta of lupin hull was low, showing predominantly liquid-like viscoelastic properties. On the other hand, lupin cotyledon fibre retarded bile acid release due to increased viscosity of the in vitro digesta, which was linked with high contents of pectic polymers forming an entangled network. Molecular interactions with bile acids were not measured for the hull but for the cotyledon, as follows: A total of 1.29 µmol/100 mg DM of chenodesoxycholic acids were adsorbed. Molecular interactions of cholic and chenodesoxycholic acids were evident for lignin reference material but did not account for the adsorption of the lupin cotyledon. Furthermore, none of the isolated and fractionated cell wall materials showed a significant adsorptive capacity, thus disproving a major role of lupin cell wall polysaccharides in bile acid adsorption