Design and functionality of a prototype for cold needle perforation of wheat

Wheat is a vital crop in global food security, but up to 25% of the wheat harvested is contaminated with mycotoxins that have detrimental effects on human health. To address this issue, biological detoxification strategies have been developed using microorganisms and enzymes. Perforating the whole wheat kernel using cold needle perforation (CNP) followed by a detoxification step could be a promising approach to reduce cross-contamination during the milling of mycotoxin-containing wheat. In this study, a pilot-scale CNP prototype was developed to perforate wheat kernels, and its effectiveness was evaluated. The height-adjustable perforation unit consists of 3120 needles. The throughput of the CNP prototype was adjusted to 6 kg/h, and the kernels were perforated for 1, 5, or 10 cycles. The results show that the CNP prototype effectively perforates wheat kernels, as evidenced by the significant increase in pore count. Fluorescence microscopy confirmed the penetration of particles in the size range of enzymes and microorganisms into the kernel. This study demonstrates the successful scale-up of CNP for wheat kernel perforation and highlights the potential of CNP as a cost-effective and efficient method for the biological detoxification of mycotoxin-contaminated wheat

Ohmic heating - a novel approach for gluten-free bread baking

Gluten-free (GF) batters usually present several technological challenges that limit the performance during conventional baking and the resulting product quality. Due to the volumetric heating principle and faster heating rates, ohmic heating (OH) may be advantageous compared with conventional baking. Therefore, the potential of using ohmic heating as a novel approach for gluten-free bread baking was explored. In detail, the effect of different OH process parameters (power input, holding time) on the chemical and functional properties (specific volume, crumb firmness and relative elasticity, pore properties, color, starch gelatinization) and digestibility of breads was investigated. Results showed that GF breads could benefit from the uniform rapid heating during processing, as these breads showed superior functional properties (specific volume, 2.86-3.44 cm3/g; relative elasticity, 45.05-56.83%; porosity, 35.17-40.92%) compared with conventional oven-baked GF bread (specific volume, 2.60 cm3/g; relative elasticity, 44.23%; porosity, 37.63%). In order to maximize bread expansion and the OH performance, it was found that the OH process could be improved by applying the electrical energy in three descending power steps: first step with high power input (in this study, 2–6 kW for 15 s), followed by 1 kW for 10 s, and 0.3 kW for 1–30 min. In total, ohmic baking only needed a few minutes to obtain a fully expanded GF bread. The determination of pasting properties and starch digestibility demonstrated that these breads were comparable or even superior to GF breads baked in a conventional baking oven

Evaluation of innovative technological approaches to replace palmoil with physically modified Swiss rapeseed oil in bakery products

Palm fat is often used in baked goods because of its relatively low cost, and its positive impact on texture and shelf life. Demand for alternatives has risen in recent years due to concerns about the ecological and social sustainability. This is a challenge for the bakery industry since palm oil possesses unique properties. In this study, unhydrogenated rapeseed oil was processed using novel physical technologies, such as wax crystallisation, stabilized foaming and Pickering emulsions, in order to simulate palm oil properties. Analysis showed that while the initial viscosity of the fat substitute products was low compared to palm fat, the fat replacement products behaved very similarly to palm fat in the baking experiments. The resulting biscuits baked with emulsified rapeseed oil and rapeseed oil complemented with wax crystals were judged to be suitable replacements for palm fat in terms of processability, as well as analytical and sensory assessment

Potential of a techno-functional sourdough and its application in sugar-reduced soft buns

Functional lactic acid bacteria (LAB) as starter cultures used in sourdough fermentation have been researched for years. This study evaluated the LAB strains Leuconostoc citreum DCM65 (mannitol, exopolysaccharide producing, antifungal activity) and Lactiplantibacillus plantarum subsp. plantarum MA418 (amylolytic activity) and their potential as single or co-culture starters in sourdough fermented buns containing different levels of sugar (control 9% and reduced 0, 3, 6%). Cell counts, pH development, and organic acids were determined before and after sourdough fermentation (30 °C, 24 h) and physical properties (color, volume, pore structure, and texture) of buns produced thereof were determined after baking. Sourdoughs started with DCM65 and/or MA418 developed up to log 9.2 CFU/g presumptive LAB after 24 h, assertiveness of the added starter cultures species was confirmed by MALDI-TOF MS. Acetic acid and mannitol were only detected in sourdough fermented with DCM65 (single or co-culture) up to 2.5 mg/g and 9.8 mg/g, respectively. The starter cultures applied influenced physical properties of buns. Sourdough buns started with MA418 had higher volume and slice area, and softer crumb; in contrast, buns fermented with DCM65 had a finer pore structure. In summary, both starter cultures showed high potential in sourdough buns with reduced sugar content

Impact of selected baking and vacuum cooling parameters on the quality of toast bread

Erworben im Rahmen der Schweizer Nationallizenzen (http://www.nationallizenzen.ch)​Vacuum cooling of baked goods can deliver many advantages in terms of product quality and productivity, such as higher volumes and shorter cooling times. However, the associated high costs and the need to adjust baking protocols are of relevance and more information is needed. This paper examines the influence of two main baking protocol parameters on the quality of toast bread, i.e. oven temperature and baking time reduction. Resulting toast bread characteristics including specific bread volume, concavity, browning index, crust and crumb hardness and aw-value were analysed as well as process-dependent core temperature and water loss. In order to compensate for water loss during vacuum cooling and still achieve optimal toast bread quality, a final bread core temperature of 98 °C at the end of baking gave best results, regardless of oven temperature. It was further shown that cooling time can be reduced by a factor of 10 if the baking protocol is optimally adjusted, hinting at a huge potential to increase productivity for industrial applications. In summary, it can be stated that vacuum cooling requires a tailored reduction in baking time in order to compensate for water loss from vacuum cooling while retaining sufficient structural cohesion to resist deformation of the bread

Naked barley - functional grain - functional food

Trotz vieler positiver Eigenschaften spielte Nacktgerste in der Humanernährung bis dato eine untergeordnete Rolle, was in erster Linie auf die begrenzten Backeigenschaften zurückzuführen ist. Ziel der vorliegenden Arbeit war es ein reines Nacktgerstenbrot mit ansprechenden sensorischen Eigenschaften herzustellen, um somit die positiven Eigenschaften der Nacktgerste der Allgemeinheit zugänglich zu machen. Nacktgerste ist reich an löslichen und unlöslichen Ballaststoffen, die sich in vielfältiger Weise positiv auf die Gesundheit auswirken. Besonders hervorzuheben ist dabei die Fraktion der -Glucane, die nicht nur in quantitativer Hinsicht hervorsticht sondern auch zahlreiche gesundheitsfördernde Eigenschaften aufweist. Die cholesterinsenkenden und blutzuckerregulierenden Attribute von -Glukanen werden in Zukunft auch in Europa mit Health Claims deklarierbar sein, was die Attraktivität von Lebensmitteln reich an -Glucan sowohl in gesundheitlicher als auch in wirtschaftlicher Hinsicht erhöht. Neben Ballaststoffen weisen gefärbte Nacktgerstesorten zusätzliche Sekundäre Pflanzenstoffe wie Polyphenole, Carotinoide und Melanine auf, die durch ihre antioxidativen Eigenschaften ein beachtliches anticancerogenes Potential besitzen. Um die positiven Eigenschaften der Nacktgerste nutzen zu können, war es notwendig, eine Brotrezeptur zu finden, die trotz der mangelhaften Backeigenschaften von Nacktgerstenmehl zu einem ansprechenden Ergebnis führt. Es konnte gezeigt werden, dass die Verwendung von Quellmehl, Malzmehl, Margarine, Säuerungsmittel und Enzymen die Eigenschaften von reinem Nacktgerstenbrot maßgeblich verbesserte und die Brote somit zufriedenstellende sensorische Eigenschaften aufwiesen. Um die Backqualität von Nacktgerstenmehl auch ohne langwierige, material- und zeitintensive Backversuche abschätzen zu können, wurden außerdem teigrheologische Tests mit verschiedenen Nacktgerstesorten durchgeführt. Die Farinogramme ermöglichten Unterschiede zwischen den einzelnen Mehlen zu verdeutlichen. Eine Kombination von Farinogrammen und weiteren chemischen Analysen korrelierte mit den Ergebnissen der durchgeführten Backversuche. Es konnte gezeigt werden, dass es möglich ist, die Backeigenschaften von Nacktgerstenmehlen auch ohne Backversuche zuverlässig abzuschätzen, was besonders in der Pflanzenzucht große Vorteile mit sich bringt.Despite numerous positive effects naked barley is hardly used in human nutrition. One putative reason are the limited backing qualities of naked barley flour that impede food production more. The aim of this work was to produce pure naked barley bread with attractive sensory attributes to make the positive properties of this crop accessible and promote the use of naked barley in human nutrition. Naked barley is rich in soluble and insoluble dietary fibres that have several health supporting effects. -glucans that represent the main dietary fibre fractions of naked barley lower blood cholesterol help to maintain blood sugar levels within the normal range. Recently a health claim relating to these positive effects of -glucans was established by EFSA; consequently, the use of -glucan rich foods will be linked to economic and health-related benefits. Moreover, colored naked barley varieties exhibit several secondary plant metabolites like polyphenols, carotenoids and melanins with a considerable anticancerogenic potential that underlies their function as free radical scavengers. To make the positive effects of naked barley usable it was necessary to find a bread formulation that leads to satisfying results despite its poor baking qualities. It was shown that the use of pregelatinized flour, malt flour, margarine, acidifier and enzymes in pure naked barley bread improved the sensory properties and resulted in appealing bread. To predict the baking qualities of naked barley flour without time-, raw material- and labour-intensive backing trials some naked barley varieties underwent dough-rheological tests. The farinograms illustrated differences between the examined flours. A combination of farinograms and chemical analysis correlated with the results of the conducted baking trials. It was shown that the baking qualities of naked barley flour could be estimated without baking experiments which facilitates plant breeding.by Mathias KinnerAbweichender Titel laut Übersetzung der Verfasserin/des VerfassersWien, Univ. für Bodenkultur, Diss., 2010OeBB(VLID)193126

Effectiveness of perforation methods for wheat kernels

Wheat is an important staple food worldwide, but often contaminated with moulds, which in specific cas es, form toxic mycotoxins as secondary metabolites. The aim of this study was to investigate different pre processing methods of wheat kernels that allow active agents such as functional microorganisms and en zymes to pass through the water-repellent hyaline layer in order to break down possible mycotoxins into less or non-toxic compounds. To be able to assess the processing efficacy, a qualitative visualisation meth od was developed and implemented. A wide range of processing techniques to perforate the outer layers while maintaining structural integrity of the kernel were tested, including ohmic heating, pulsed electric fields (PEF), ultrasonication, cold needle perforation (CNP), heat stress and steam explosion. It was shown that both the application of PEF as well as CNP are promising paths to perforate the outer wheat layers. The effectiveness of CNP was shown through a combined microscopic approach involving scanning elec tron microscopy and fluorescence microscopy with fluorescing particles in the size range of both enzymes and lactic acid bacteria