Nadine Schulze-Kaysers

• Doctor of Engineering
• Lecturer Food Sensory at University of Bonn

Aquafaba, the cooking water of chickpeas and other pulses, is used as a vegan egg white substitute because of its favorable technofunctional properties. Nonetheless, its application is often restricted by a “beany” flavor and poor foaming properties compared to egg white. To overcome these limitations, aquafaba was fermented with two edible basidio...

Due to a widespread consumer reluctance toward synthetic food dyes, the interest in natural compounds from plants has increased. This study aimed to optimize the oxidation process between chlorogenic acid (CQA) and tryptophan (Trp) using sodium periodate (NaIO4) to obtain a red-colored pigment. The impact of temperature and different ratios of Trp...

Low morphine yielding winter ('Zeno Morphex') and summer ('Viola', 'Mieszko', 'Borowski') poppy varieties were investigated for their chemical composition and sensory properties. The oil content of the 13 seed samples as well as that of fatty acids, tocopherols, and volatile compounds in the respective oils were determined, and the sensory profiles...

Pink guava (Psidium guajava L.) is a highly consumed fruit in tropical countries. Despite of interesting research on health effects of this fruit, investigations into the profile of secondary plant metabolites are scarce. In this study, the phenolic compounds in the peel and flesh of pink guava were characterized by ultra-high-performance liquid ch...

The objective of this work was to determine the phenolic profile of Schinus terebinthifolius and S. molle fruits and to develop a reliable method for the differentiation of these two similar spices both known as pink pepper. Anthocyanins, biflavonoids and gallotannins, some of which are reported for the first time in these species, were identified...

Alk(en)ylresorcinols (AR), a class of phenolic lipids, are regarded as antifungal compounds showing high potential for the use in plant protection, especially against Fusarium head blight (FHB). In view of the very limited knowledge of the activity of single AR against Fusarium species, the antifungal effect of crude extracts, fractions and isolate...

Lactating ruminants require an adequate supply of absorbable amino acids for the synthesis of milk protein from two sources, that is crude protein (CP) synthesized microbially in the rumen and ruminally undegraded CP (RUP) from feed which can both be digested in the small intestine. Several chemical and physical methods have been identified as bein...

Pigments of pericarp and pulp of pink guava (Psidium guajava L. cv. ´Criolla´) were investigated to elucidate the profile and the accumulation of main carotenoids during four stages of fruit ripening by using HPLC-DAD and APCI-MS/MS analysis. Seventeen carotenoids were identified and changes in their profile during fruit ripening were observed. The...

Response surface methodology was employed to investigate the effects of pressurized liquid extraction (PLE) parameters on the recovery of phenolic compounds (anthocyanins, biflavonoids) from Brazilian pepper (Schinus terebinthifolius Raddi) fruits. The effects of temperature, static time, and ethanol as well as acid concentration on the polyphenol...

Alkylresorcinols (AR) are a class of phenolic lipids which are found in a number of plants and microorganisms and which are associated with various biological activities. In view of the very limited availability of reference compounds, we developed a process for the isolation of AR from rye bran. For this purpose, a crude extract was subjected to d...

Sunflower extraction meal (SEM) is an economically interesting protein source. During alkaline extraction of proteins, the presence of chlorogenic acid (CQA) in the meal gives rise to the formation of o-quinones. Reactions with nucleophiles present in proteins can lead to green discoloration. Although such reactions have been known for a long time,...

The Anacardiaceae is a plant family that includes numerous species of high economic importance, e.g. mango, cashew, pistachio, and pink pepper as well as plants that are of local importance. Members of this family have been known as polyphenol-rich, however, this early view was based mainly on the results obtained using relatively basic analytical...

Adsorption behavior of six flavonols derived from onion processing residues was evaluated using statistical design of experiments. Adsorption experiments were conducted at temperatures varying between 25 and 65 C and pH-values of 2 to 6. Adsorption capacities and adsorption rates of the individual flavonols were determined by fitting the pseudo-sec...

The objective of this study was to characterize the phenolic composition of Brazilian pepper (Schinus terebinthifolius Raddi) exocarp extract. Using UHPLC-DAD-MS/MS analysis, four anthocyanins, three biflavonoids, gallic acid, and two types of hydrolyzable tannins (galloyl glucoses, galloyl shikimic acids) were tentatively identified. The structure...

Encapsulated phenol extracts from industrial processing residues of onions and apples are discussed as health promoting food additives. Prerequisite for their use in human/animal nutrition is the quantitative liberation of the phenols during digestion. In the present in vitro study we, thus, determined the release rate of a variety of spray dried p...

Polyphenols are a chemically diverse group of secondary metabolites that occur ubiquitously in plants. As a result of their pronounced structural diversity and hence their greatly differing chemical and physical properties, their analysis has proved to be challenging. In fruits and fruit-derived products, phenolic compounds are characterized and qu...

This study describes the evaluation of the anti-browning effect of 36 plant extracts, divided into three groups: (1) Fruits, vegetables, and oil seeds, (2) herbs and tea plants, and (3) medicinal plants, on minimally processed fresh apples. The extracts were applied to freshcut apple slices as dipping solutions. Development of browning was analyzed...

Olive leaf extract (OLE) contains high amounts of oleuropein and hydroxytyrosol. The antioxidant capacity of these polyphenols makes OLE a promising ingredient for functional food. OLE causes very strong bitterness perception and can therefore only be formulated in low concentrations. In this research, bitter detection and recognition thresholds of...