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Rice beverages are commonly fortified with minerals to improve their nutritional value. However, the effect of fortification on mineral bioaccessibility is poorly understood. Thus, the effects of fortification of a rice beverage on mineral concentration and bioaccessibility using calcium carbonate (CaCO

Table salt fortified with KIO

Grass pea (Lathyrus sativus L.) seeds contain an endogenous neurotoxic non-proteinogenic amino acid, β-N-oxalyl- l -α,β-diaminopropionic acid (β-ODAP), a major limiting factor-for their human consumption. Furthermore, phytate (IP6), a well-known antinutrient is present in concentration capable of hindering bioavailability of iron (Fe), zinc (Zn), calcium (Ca), phosphorus (P) and other micronutrients from the seeds. Due to the reported capability of high hydrostatic pressure (HHP) to reduce the content of certain antinutritional/toxic agents in seeds and grains, the impact of HHP on the reduction of β-ODAP and IP6 were investigated. The contents of β-ODAP of accessions from different regions in Ethiopia were found to be in the range of 51.94 to 806.52 mg/100 g. Accession (GF1- Alemu, AK) exhibiting the highest β-ODAP content was selected for HHP treatment in soaked and batter forms using Central Composite Face Centered Design of experiments. The best HHP conditions in respect to β-ODAP reduction were also applied to the accession (GP-240038) with the lowest β-ODAP-content, a genetically improved variety (Wassie) and a variety from Germany (GR). The HHP treatment at 600 MPa for 25 min of seeds soaked for 6 h and 12 h exhibited the maximum reduction of β-ODAP (232.11 mg/100 g) and IP6 (21.11 mg/100 g) respectively. The combined incremental effect of pressure and soaking time resulted in a more significant (p ≤ .001) reduction in both compounds than the interaction of pressure with holding time (p ≤ .05). A reduction of β-ODAP from 36.00 to 71.22% by soaked-HHP treatment was observed. β-ODAP reductions were always higher for soaked compared to batter grass pea seeds. IP6 contents after HHP treatment ranged from 33.65 mg/100 g to nill. It can be concluded that pressure, soaking and holding time as well as the grass pea seed accession/variety had great impact on molecular structure changes, enhancement of enzyme activity and reduction in β-ODAP and IP6 content.

When carrier systems like solid lipid nanoparticles (SLN) are added to a protein rich food matrix adsorption of protein to the particles alters the surface properties of SLN which in turn can alter the properties of the whole system. Thus, the effect of the SLN composition on the protein adlayer (protein corona) is important to understand. The adsorption of β-lactoglobulin (βLG) to unloaded SLN and SLN loaded with ferulic acid or tocopherol was studied at pH 5.7 and particle:protein ratios of 2:1 to 10:1 (w/w) by centrifugation, AF4 and ultrafiltration (UF). Up to 10% of the βLG was strongly bound to SLN whereas 40–80% of the βLG formed a loose adlayer. The amount of bound βLG was increased by the presence of tocopherol and decreased by the presence of ferulic acid. The adsorbed protein layer thus depends on SLN characteristics governed by encapsulated compounds.

Cowpea and rice were evaluated for their suitability as an alternative to wheat in the production of ice cream baskets (ICB). The experiment was conducted according to a 23 full factorial design using water (WT; 10 or 15 mL), rice flour (RF; 15 or 20 g) and cowpea flour (CF; 15 or 20 g) as variables. The ICB consisted of 6.4–10% moisture, 10.1–11.9% protein, 75.2–78.4% carbohydrates, 2.2–3.7% lipids. The ash content was determined to be 1.2–1.5%, the energy content 368.7–382.0 for kcal and Aw 0.308–0.475. The ICB showed a bronze-orange color resulting from the presence of carotenoids (4.9–9.3 μg/g W) from the crude palm oil used. Texture and sensory analysis of the ice cream baskets revealed a crispy, brittle and hard nature. The highest acceptability (≥4) in the sensory evaluation was obtained for ice cream baskets produced with 20 g of rice flour, 20 g of cowpea flour and 15 g of water. Thus, the developed gluten-free ice cream baskets are an excellent alternative to wheat-based ones.

Edible solid lipid nanoparticles (SLN) stabilized by a mixture of food grade emulsifiers (soy bean lecithin, Tween 20, sucrose stearate) were added to o/w emulsions previously stabilized by anionic SDS, non-ionic Tween 20 or cationic CTAB. The aim of the study was to understand the fate of both SLN and oil droplets in these mixtures focusing on the impact of the surfactant used to stabilize the emulsion. The presence of SLN in emulsions led to increased emulsion stability as reflected by droplet size measurements and accelerated creaming experiments. This could be attributed to an increase in the viscosity of the sample, but also to changed properties of the o/w interface. Zeta potential measurements revealed that the surfactant composition at the o/w interface had changed in SDS and CTAB stabilized but not in Tween 20 stabilized emulsions. SLN remained detectable in the continuous phase of each emulsion system over three weeks of storage but were not detected at the o/w interface of oil droplets. The particle size of the SLN remained unchanged whereas their zeta potential increased in SDS and CTAB stabilized emulsions to a similar magnitude (+/− 68 mV) but opposite signs. The melting temperature and melting enthalpy of SLN decreased in emulsions indicating that part of the lipid matrix was dissolved by oil from the emulsion. Accordingly, a time-dependent transfer of crystalline triglycerides originating from the SLN into the oil phase of separated model emulsion systems was verified.

The release and partitioning of encapsulated compounds from solid lipid nanoparticles (SLN) to other matrix constituents was investigated in o/w emulsions stabilized by different surfactants (CTAB, SDS, Tween 20) by confocal laser scanning microscopy (CLSM) and electron paramagnetic resonance spectroscopy (EPR) spectroscopy. CLSM images revealed that the encapsulated probe Coumarin 6 (C6) was located in the oil droplets after SLN were mixed with the different emulsions. The EPR spin probe TEMPOL‐benzoate (TB) showed different dynamics as a function of its specific solubilization sites in SLN. Four different populations of the spin probe could be separated giving the smallest population in the aqueous environment and the major population at the SLN interface. Two further populations were associated with differently crystalized lipid environments. This implies that both loosely structured regions with α- and β’-polymorphs and environments of β-polymorphs are present in SLN. In separated model emulsion systems, a prolonged release of TB from SLN was evident which predominately originated from the SLN interface. The released TB partitioned into the oil phase (25%) and into the o/w interface (30–45%), regardless of the presence or absence of additional surfactant micelles. Hence, these edible SLN may be used as delivery system for bioactive compounds in food emulsions with low impact of the surfactant used to stabilize the emulsion. The partial redistribution of the encapsulated compounds should be taken into account, but can also offer benefits when a prolonged release of lipophilic additives is desired.

The effect of iodine present in 1.0% table salt in combination with the use of starter cultures in sauerkraut fermentations were investigated in order to determine whether iodine interferes with lactic acid bacteria responsible for the fermentation. The effect of iodine was tested in fermentations performed using selected starter cultures or without starters (spontaneous fermentation). Lactobacillus plantarum and Leuconostoc mesenteroides used as starters at levels of ca. 1 × 107 cfu ml−1 led to a quick establishment of lactic acid bacteria (LAB) as predominant microorganisms, reaching 1 × 109 cfu ml−1 after 24 h decreasing the pH to below 4.0. In contrast, LAB counts in control fermentations without starters increased slower from 1 × 105 cfu ml−1 to 1 × 109 cfu ml−1 and a pH reduction below 4.0 was achieved only after 3 days fermentation. A metagenomic investigation showed a more diverse bacterial community in fermentations without starters, consisting of enterobacteria and pseudomonads in the first days of fermentation, and of LAB such as lactococci in the later stages. In fermentations with starters, lactobacilli predominated. Leuconostocs also occurred, but at much lower sequence abundance than lactobacilli, and thus were not able to predominate. Determination of iodine in the fermentation with starter bacteria and with iodized salt showed that the fermentation did not affect iodine concentration. The use of iodized salt did not statistically significantly influence microbial populations in the fermentation. Thus, there is no basis for the popular held belief that the use of iodized salt inhibits the growth of the bacteria important for the sauerkraut fermentation. A statistically near significant effect (p = 0.06), however, was noted for the effect of iodine on yeasts and mould populations in the fermentations performed without starter cultures. As sauerkraut is usually produced without starters, this should be further investigated.

Consumer demands for healthier food have been growing over the last decades. Enriching conventional food with bioactive substances is one option to fulfill these demands. Solid lipid nanoparticles (SLN) are known as carrier systems for lipophilic bioactives. However, due to their large interface, they likely interact with the food matrix. We therefore studied how SLN affect the properties of cold set β-lactoglobulin (BLG) gels. BLG or Tween 20, typical excipients used for stabilizing SLN in suspensions, was applied to reduce or promote interactions between SLN and the protein matrix. Tween 20 stabilized SLN were incorporated before or after the heat treatment of the protein, BLG stabilized SLN were added after the heat treatment. Gels were analyzed regarding their mechanical properties, syneresis, and microstructure. All gels showed fine stranded network morphology. BLG stabilized SLN increased the Young's modulus of the gels with increasing particle content. They caused thick lamellae and ramifications within the gel. Their absence in the syneresis water confirmed that they acted as bound particles. Tween 20 stabilized SLN, incorporated before heat treatment, did not affect the Young's modulus. By contrast, Tween 20 stabilized SLN added after heat treatment decreased the Young's modulus and resulted in disrupted lamellae. Tween 20 stabilized SLN were washed out during syneresis to a certain extent. The results indicate the integration of BLG stabilized SLN in the network and their function as bound particles. SLN, stabilized by Tween 20, did not participate in the gel network and acted as unbound particles.

The potential to use abattoir’s rumen fluid as a source to produce a carbohydrate degrading enzymatic feed additive by using spray-drying technique was studied. Rumen contents were taken from the slaughterhouse and powdered by spray drying with different hydrocolloids including sodium alginate (RA), guar gum (RG), chitosan (RC) and maltodextrin (RM) in two ratios (0.5 and 1% (w/v)). Fresh (RF) and spray dried rumen fluid without hydrocolloid materials (RN) were considered as controls. Residual activities compared to those measured in the fresh rumen fluid ranged from 68.6 (RC0.5) to 92.5% (RM1) for carboxymethyl cellulase, from 53.4 (RC1) to 73.2% (RM1) for avicelase, from 59.8 (RA0.5) to 84.6% (FM1) for amylase, and from 63.7 (RG0.5) to 95.8% (RM1) for filter paperase. Spray drying in the absence of a hydrocolloid resulted in 81.3% residual activity of carboxymethyl cellulase, 63.3% of avicelase, 68.6% of amylase, and 73.0% of filter paperase. The addition of 1% (w/v) maltodextrin was shown to retain the highest enzyme activities after spray drying. In addition, a dry matter degrading test was carried out to show the ability of the enzyme preparations at two concentrations (1 or 2% solution in phosphate buffer) to digest a typical dairy cow diet. At 1%, RF resulted in highest dry matter digestibility (P

This study was carried out to establish Saccharomyces cerevisiae, xylanase, and their mixture as environmentally friendly feed additives that can reduce enteric biogas production. Rumen liquor was obtained from two rumen cannulated Holstein steers, two rumen cannulated Creole goats and two rumen cannulated Rambouillet sheep. The basal ration was supplemented (per g dry matter (DM)) with 2 mL xylanase, 4 mg S. cerevisiae or a mixture of both additives. There was no interaction (P > 0.05) between inoculum source and additive type. Inclusion of additives resulted in higher (P = 0.045) asymptotic gas production (GP) with sheep inoculum. Furthermore, higher (P

This study presents an experimental investigation of the effect of corn grain replacement with prickly pear cactus and M. oleifera leaf extract in ruminal diets. In the control diet, 40 and 70% of corn grain was substituted with prickly pear cactus, while the level of M. oleifera leaf extract was varied from 0 to 1.8 mL/g dry matter. A significant interaction between experimental diet and dosage of M. oleifera leaf extract was observed for methane, carbon dioxide, and total gas production. An increase in the composition of pear cactus in the diet resulted in a significant decrease in carbon dioxide, methane, as well as the total gas production. A decrease in lag time of gas production was also observed. The asymptotic methane production and the rate of methane production decrease in all the diets with the increase in M. oleifera leaf extract doses. Addition of M. oleifera leaf extract to the control diet resulted in a decline in carbon dioxide production, while the reverse was the case when M. oleifera leaf extract was added to pear cactus containing diet. Therefore, replacement of corn grain with pear cactus and the addition of M. oleifera leaf extract resulted in a decrease in the production of greenhouse gases. This is a promising formulation for ecofriendly livestock diet.

Background Consumption of protein-based food products has a key role in the improvement of human health. The crosslinking agent microbial transglutaminase (mTGase) is an effective and promising tool to modify animal proteins used in the food industry. Improvement in the gelation process, physicochemical and textural quality, and consumer's demand of protein-based food products could be attained by combining mTGase and some non-conventional food processing technologies. Scope and approach New perspectives and key areas for future research in the development of high-quality food proteins and protein-based products as a function of interaction effect of mTGase and some new processing techniques (e.g. high pressure processing (HPP), ultrasound, microwave (MW) and ultraviolet (UV) irradiation) are reviewed. The effect of conventional thermal and emerging processing methods on the mTGase crosslinking activity and protein gel functionality are also compared. Key findings and conclusions The crosslinking density and functional properties of protein gels can be strongly promoted by the synergistic action of mTGase and innovative processing methods. Compared to the conventional heating, HPP with further increase of mTGase affinity to proteins can result in products with better physicochemical quality and more complex and firmer gel structure. The yield, water holding capacity, surface hydrophobicity, strength, and viscoelastic characteristics of mTGase-catalyzed protein gels can be significantly increased by ultrasonication treatments. mTGase-crosslinked hydrogels subjected to high-intensity ultrasonic pretreatment have potential to be used as delivery vehicles for a wide spectrum of bioactive compounds. The application of MW and UV light can substantially improve the surface, textural and structural features of gels generated by mTGase-technology.

The effect of equine fecal inocula on the in vitro gas, methane (CH4), and carbon dioxide (CO2) production was elucidated in the present study. Fecal inocula were obtained from four Azteca horses (aged 5–8 years, 480 ± 20.1 kg). In vitro fermentation (up to 48 hours) was performed with substrate consisting of 50% (w/w) oat straw and 50% (w/w) of a commercial concentrate in the presence of a commercial Lactobacillus farciminis product (0–6 mg/g DM of substrate). Incorporation of L. farciminis resulted in increased levels of asymptotic gas (GP), CH4, and CO2 production (P .05; quadric, P > .05). Furthermore, a slight reduction in fermentation pH (linear, P = .029) and higher metabolizable energy values (P = .001) were obtained with L. farciminis supplementation in a dose-dependent manner. No significant impact of L. farciminis on dry matter degradability values was estimated (P > .05). In vitro gas, CH4, and CO2 production were increased (linear, P ≤ .001) in the presence of L. farciminis from 6 hours of incubation onward. In conclusion, addition of L. farciminis at a dose-dependent manner (2–6 mg/g DM of diet) was observed to be persuasive in terms of attaining amicable hindgut fermentation by improving fecal gas kinetics viz. gas, CH4, and CO2 production without any side effect.

The consumption of ready to eat vegetable salads among consumers in developing countries has increased with the change in life style pattern. However, food borne disease linked to these salads poses safety threats. Studies have shown the occurrence of various microbial pathogens which includes Escherichia coli, Listeria monocytogenes, coliforms , Salmonella etc. in these types of ready to eat vegetable salads. In order to overcome these safety threats, to control the microbial pathogens and to enhance the shelf life, different techniques like modified atmospheric conditions, refrigeration, innovative technologies etc. are exploited. This review insight on pathogenic prevalence of ready to eat vegetable salads in developing countries and technological advances used to counter these pathogens.

Microbial transglutaminase (MTGase) has been currently utilized to form new food structures and matrices with high physicochemical stability. Incorporation of this multi-functional enzyme into structural composition of milk protein-based products, such as cheese and ice cream, can not only be a successful strategy to improve their nutritional and technological characteristics through intramolecular cross-linking, but also to reduce the production cost by decreasing fat and stabilizer contents. The recent research developments and promising results of MTGase application in producing functional formulations of cheese and ice cream with higher quality characteristics are reviewed. New interesting insights and future perspectives are also presented. The addition of MTGase to cheese led to significant improvements in moisture, yield, texture, rheology and sensory properties, without changes in the chemical composition. Furthermore, pH value of ice cream is not affected by the MTGase treatment. Compared to untreated ice creams, application of MTGase significantly promotes consistency, fat destabilization, overrun and organoleptic acceptance, while a substantial reduction in firmness and melting rate of samples was observed. The addition of MTGase to cheese and ice cream-milk provides reinforcement to the protein matrix and can be considered as a novel additive for improving the physicochemical and organoleptic properties of final products.

Nanoemulsions are submicron sized systems utilized in the food and pharmaceutical industries for the delivery of active ingredients. Compared to other emulsion-based systems (e.g. conventional emulsions), nanoemulsions have shown to be more stable to environmental and process stresses due to their large active surface area, but are also susceptible to destabilization, after prolonged storage at non-optimal temperatures, from some mechanisms (e.g. Ostwald ripening). Several studies have been conducted to improve the stability of nanoemulsions, such as adding carbohydrates to the formulation. This review briefly explores the potential application of pectin, an anionic polysaccharide, for the stabilization of nanoemulsion systems.

Small plastic particles are found ubiquitously in marine and freshwater ecosystems and consequently, their inhabitants. When aquatic animals are consumed as seafood, human exposure to those plastic particles is possible. However, only a few studies, applying largely different analytical procedures, assessed microplastics content in the edible part of seafood. In this study, ten protocols for the extraction of microplastics from biota were chosen and tested for their suitability to digest the edible part of a broad range of seafood species. The following criteria were used for this assessment: 1) feasibility to filtrate the entire digested sample with one filter of approximately 1 μm pore size, 2) effect of reagents applied during the sample preparation on the polymer integrity as assessed by means of infrared and Raman spectroscopy as well as pyrolysis gas chromatography mass spectrometry, 3) total sample preparation time and the possibility to avoid the use of expensive reagents. The most suitable protocol was found to be an enzymatic-alkaline approach, consisting of a quick hydrolysis of proteins with pepsin for 2 h and a consecutive alkaline hydrolysis for 4 h, both at 37 °C for most of the tested seafood species. Digestion efficiency of the optimised protocol was tested with fish fillets and soft tissues of commercially relevant molluscs and crustacean species. Compared to most other protocols described in literature, an adequate digestion of the seafood matrix was achieved faster without being significantly more cost- or labour-intensive. Moreover, only negligible degradation of eleven commercially relevant polymers excluding polyacrylonitrile was observed. Polymer integrity was assessed by a change in particle weight or surface as well as spectroscopic and chromatographic data. The optimised sample preparation protocol aims to support future method standardisation efforts in order to assess the dietary uptake of microplastics in humans.

The objective of the present study was to determine the shelf-life of minimally-processed fresh-cut apples treated with anti-browning agents under modified atmosphere packaging. Shelf-life is calculated by application of mathematical models with product quality attributes such as: pH; soluble solids content (SSC); CIELab color parameters; sensory evaluation; and microbial spoilage (Salmonella spp., Staphylococcus aureus, Sulfite-Reducing Clostridium, Enterobacteriacae, Escherichia coli, Aerobic mesophilic bacteria (AMB), yeast, mold, Listeria monocytogenes). Golden Delicious and Cripps Pink apple cultivars were individually treated with one of several anti-browning treatments and packaged in a modified atmosphere (N2 = 90.5%; CO2 = 2.5%; O2 = 7%), and stored at 4 °C. The treatments were; 1) non-treated (control); 2) dipping in a mixture of ascorbic and citric acids for 3 min with and without ultrasound (40 kHz, 3 min) treatment; and 3) Ca-ascorbate with/without ultrasound (40 kHz, 3 min) treatment. Results revealed that Cripps Pink was the most suitable variety for minimally-processed fresh-cut product. All the investigated treatments were equally effective in improving the quality of the product compared to the control. Shelf-life predictive models were developed based on the following quality attributes: apple cultivar, anti-browning treatment, color parameters, sensory evaluation, pH, and SSC. Maximum growth rates for Enterobacteriacae and Aerobic mesophilic bacteria were 0.25 ± 0.02 log CFU/g/day and 0.46 ± 0.02 log CFU/g/day, respectively. In order to optimize fresh-cut production, these models can be useful tool for predicting the longest shelf-life time with monitoring microbial activity during production. All models are freely available on-line (“Anti-browning Apple Calculator – C.A.P.P.A.B.L.E.©”; apple.pbf.hr or 31.147.204.87).

It is of utmost importance, that reliable exposure data about the migration behavior of nanoparticles are collected in order to provide adequate information for the safety assessment of engineered nanoparticles (ENPs) used in the food packaging sector. The objective of this study was to evaluate the migration behavior of silver nanoparticles (AgNPs) from model food packaging films with varying nanosilver content into three different food simulants (water, 10% ethanol and 3% acetic acid). The overall silver migration determined by classical inductively coupled plasma mass spectrometry (ICP-MS) analysis was dependent on the silver content of the films, the food simulant used and the contact time and temperature applied. Furthermore, single particle ICP-MS analysis was applied in order to detect and quantify migrated AgNPs selectively. As coexistent silver ions in the migration samples had an impedient effect (decreased signal-to-noise ratio), an optimized analytical approach was developed by online-coupling of asymmetric flow field flow fractionation (AF 4 ) to single particle-ICP-MS. The enrichment of the nanoparticle fraction and simultaneous reduction of the ionic background via AF 4 resulted in a clearly improved ICP-MS detection sensitivity, which enabled a more refined identification and size characterization of the migrated silver species. Scanning transmission electron microscopy (STEM) and energy-dispersive x-ray spectroscopy (EDS) confirmed independently the presence of AgNPs and silver/polymer heteroaggregates in the migration samples.

International audience; Edible seaweeds are a good source of antioxidants, dietary fibers, essential amino acids, vitamins, phytochemicals, polyunsaturated fatty acids, and minerals. Many studies have evaluated the gelling, thickening and therapeutic properties of seaweeds when they are used individually. This review gives an overview on the nutritional, textural, sensorial, and health-related properties of food products enriched with seaweeds and seaweed extracts. The effect of seaweed incorporation on properties of meat, fish, bakery, and other food products were highlighted in depth. Moreover, the positive effects of foods enriched with seaweeds and seaweed extracts on different lifestyle diseases such as obesity, dyslipidemia, hypertension, and diabetes were also discussed. The results of the studies demonstrated that the addition of seaweeds, in powder or extract form, can improve the nutritional and textural properties of food products. Additionally, low-fat products with less calories and less saturated fatty acids can be prepared using seaweeds. Moreover, the addition of seaweeds also affected the health properties of food products. The results of these studies demonstrated that the health value, shelf-life and overall quality of foods can be improved through the addition of either seaweeds or seaweed extracts.

The aim of this study was to estimate bioaccessibility of Ca, Fe and Mg in residues of orange, lime, and their mixture, in order to evaluate the effects of cooking in water on mineral bioaccessibility and also to determine the composition of macronutrients and myo-inositol phosphate content. The citrus samples contained on average 9.53 g/100 g moisture, 6.09 g/100 g protein, 3.23 g/100 g ash, 3.15 g/100 g lipids, 34.26 g/100 g insoluble fiber, 27.88 g/100 g soluble fiber and 25.64 g/100 g carbohydrates. The percentage of soluble and dialyzable minerals ranged from 19.36 to 77.33% and from 5.59 to 69.06% for Fe, from 33.34 to 60.84% and 14.71 to − 26.13% for Ca, and from 29.95 to 94.20% and 34.42 to 62.51%, for Mg, respectively. It was verified that cooking influenced the minerals bioaccessibility and increased the dialyzable fraction of Fe and Mg, but decreased the fraction of Ca dialysate, except to orange. No myoinositol phosphate esters were detected. The Principal Component Analysis allowed the separation of different types of citrus residues, but did not discriminate the raw and cooked samples. This study pointed the potential of citrus residue to be used for human consumption and contribute to the necessary dietary minerals and macronutrients, with high content of soluble and insoluble fibers.

This study aimed at investigating the effect of iron compounds used in whole wheat flour (WWF) fortification, both on rheological properties of the dough and on bread technological quality. Furthermore, bioaccessibility of iron (Fe), zinc (Zn) and calcium (Ca) in the final breads was determined. Rheological properties (mainly dough development time, stability, mixing tolerance index, resistance to extension and ratio number) of the dough and the technological quality of bread (mainly oven spring and cut opening) were altered. However, producing roll breads fortified with different iron compounds was still possible. NaFeEDTA (ferric sodium ethylene diamine tetra acetic acid) proved to be the most effective iron compound in the fortification of WWF, since it presented the highest levels of solubility (44.80%) and dialysability (46.14%), followed by microencapsulated ferrous fumarate (FFm). On the other hand, the microencapsulated ferrous sulfate (FSm) and reduced iron presented the lowest solubility (5.40 and 18.30%, respectively) and dialysability (33.12 and 31.79%, respectively). Zn dialysis was positively influenced by NaFeEDTA, FSm, and ferrous fumarate. As for Ca, dialysis was positively influenced by FSm and negatively influenced by FFm. The data indicated that there is a competitive interaction for the absorption of these minerals in whole wheat roll breads, but all studied minerals can be considered bioaccessible.

Potato waste, usually derived from storage and processing of potatoes, is an agricultural byproduct already used as a feed for ruminants. Its fermentation using rumen fluid, another waste product obtainable from slaughterhouses, is expected to valorize both products. Bioconversion of potato waste using rumen fluid was followed by measuring volatile fatty acids (VFAs), pH, and the extent of digestion of the potato waste as well as the nutrient composition of the solid residues after fermentation. Different ratios (1:2, 2:2, 3:2 and 4:2 w dry matter/v) of potato waste to rumen fluid were fermented in a DaisyII incubator for 12 or 24 h at 39 °C. Depending on the fermentation time and the dry mass of potato waste used for fermentation, a digestion rate between 31 and 78.8% of the potato waste (solid phase of the fermentation mixture) was obtained. Fermentation resulted also in an up to 2.5-fold increase in the concentration of VFAs in the liquid phase of the fermentation mixture. During fermentation, the pH value of the fermentation mixture dropped from 6.95 to about 4.0 (P

Background Negative pressure cavitation (NPC) extraction is a novel effective and eco-friendly technology. In this method, cavitation is generated by negative pressure and continuously introduced into the liquid-solid system to enhance the turbulence, collision and mass transfer between the extracting solvent and solid matrix. This technique was found to be efficient for improving the substrate and enzyme mixing, increasing the enzymatic hydrolysis of the plant cell wall components and improving the intracellular contents release into the extraction solvent. Scope and approach So far, several studies evaluated the feasibility of using this system alone or in combination with other extraction methods (e.g. enzyme, homogenization, microwave, ionic liquid solvents and deep eutectic solvents) for extraction of food active compounds (e.g. flavonoids, isoflavonoids, saponins, stilbenes, polyphenols and alkaloids) from plant materials. This review gives an overview of the principle of NPC method and its application alone or in combination with other extraction techniques for extraction of active compounds from plant materials. Key findings and conclusions The outcome of the studies using NPC demonstrated that this technique is a simpler procedure, requiring low cost, and provides high efficiency. It is eco-friendly, and possesses a remarkable potential application in the industrial production compared to other extraction techniques. Moreover, since this method is performed at room temperature, it can reduce or prevent the degradation of thermosensitive compounds.

Because green biosynthesis using microorganisms is advertised as a promising, eco-friendly and biocompatible approach for the production of silver nanoparticles (AgNPs), many studies were focused on the extracellular production of nanoparticles enabling an easy downstream processing. However, the influence of the culture media on extracellular AgNP synthesis was rarely investigated. In this study, the effect of various culture media and their components on the extracellular AgNP synthesis of Klebsiella pneumoniae UVHC5, Escherichia coli ATCC 8739 and Pseudomonas jessinii UVKS19) was investigated. UV-Vis spectroscopy, DLS, SEM and EDX spectroscopy were used to verify the particles formed. Culture media, bacterial supernatants and the individual medium components were added to AgNO3 solutions. After 7 days of incubation the liquids contained particles of different shapes, sizes and composition. The formation of specific particle species mainly depended on the composition of the culture media (especially the Cl- content), in which the bacteria were inoculated. Samples incubated with bacterial supernatant of STI, NB, LB or MH showed AgCl particles of cubic or star-/flowerlike shapes coated with AgNPs. In contrast, silver nanoclusters were observed in the inoculants of bacterial supernatants grown in MRS or AgNPNB. However, small effects of bacterial metabolites on the formation of the particles could be observed and indicate an influence of the media alteration by bacterial growth on the particle formation. When the individual medium components were added to AgNO3, different absorbance spectra were obtained. Therefore, we conclude that the formation of Ag/AgCl nanoparticles results from the interaction of all medium components.

Pasteurization of eggs has adverse effects on nutrient composition and functionality of egg proteins. UV processing is an alternative technology with potentially fewer adverse effects as it is less intrusive. Egg white, whole egg and egg yolk vitamins (A, B2, B5, C and E), minerals (P, Cl, K, Na, Ca, Mg, Fe and Zn) and main secondary metabolites (lutein and zeaxanthin) were examined after exposure to UV in a coiled tube UV-C reactor at doses known to achieve microbiologically stable egg fractions. The studied nutrients were fairly stable to a treatment with UV-C light with the exception of retinol, vitamin C and carotenoids, which showed loses up to 80%, 66% and 61%, respectively. Moreover, the functional properties of ultraviolet-treated eggs were investigated. Results showed a positive impact on the foam ability and foam stability, and an increase on the emulsifying activity index above 20% versus pasteurized samples. Processing with UV can maintain most of the egg nutritive properties, and retain or even improve the technological properties of foaming and emulsification in eggs. Industrial relevance: This novel UV-C system can be applied successfully to the Food Industry. UV-C does not impair nutritional damage to egg-treated products, and even improve egg functional properties.

The genetic disposition, the influencing factors of the environment as well as the development status affect the resilience of microorganisms and consequently may influence the inactivation efficiency of an UV-C pasteurization process. In this study, the effect of different growth conditions on the reduction rate of E. coli DH5α and L. plantarum BFE 5092 in Quarter-strength Ringer’s solution (QSRS) was investigated. For E. coli DH5α, the temperatures below the optimum growth temperature led to higher UV-C resistant cells, whereas incubation at 45 °C facilitated the UV-C inactivation of E. coli DH5α. However, no considerably difference in UV-C sensitivity could be observed for L. plantarum BFE 5092 incubated at the different growth temperatures applied. In addition, L. plantarum BFE 5092, being more sensitive in stationary phase, was more resistant to UV-C than E. coli DH5α. No considerably effect on the inactivation efficiency could be observed for both species with regards to the initial pH value of the growth media. The effect of various temperatures and pH values on the inactivation behavior of L. plantarum BFE 5092 was also tested and no difference in reduction rates could be observed in the range of 2-40 °C and pH 4.5-7.

Grass pea (Lathyrus sativus L.) is commonly consumed in cooked, fermented, and roasted forms in Ethiopia. However, the impacts of household processing practices on its nutrients, antinutrients, and toxic compounds have not been adequately studied. Therefore, the effects of household processing and fermentation in the presence and absence of a phytase on the contents of β-N-oxalyl-L-α,β-diaminopropionic acid (β-ODAP), myo-inositol phosphates, crude protein, minerals and the in vitro bioaccessibility were investigated. Fermentation exhibited a significant decline in β-ODAP (13.0–62.0%) and phytate (7.3–90.5%) irrespective of the presence of phytase. Pressure and pan cooking after discarding the soaking water resulted in a 27.0 and 16.2% reduction in β-ODAP. A 30% reduction in phytate was observed during germination followed by roasting. In addition, germination resulted in a significant (p < 0.05) increase in crude protein. Germination and germination followed by roasting resulted in the highest Fe bioaccessibilities (more than 25 fold higher compared to untreated samples) followed by pressure cooking and soaking. Processing also improved Zn bioaccessibilities by 50.0% (soaked seed without soaking water), 22.5% (soaked seed with soaking water), and 4.3% (germination). Thus, the processing technologies applied were capable of reducing the content of phytate (InsP6) and β-ODAP with a concomitant increase in mineral bioaccessibilities. Processing of grass peas could therefore contribute to their more widespread utilization.

To counteract iodine deficiency in the population in areas of environmental iodine deficiency table salt is often fortified with potassium iodide or iodate. However, most estimations of iodine contribution from the diet rely on calculations based on the added iodized salt and very limited experimental data about the stability of potassium iodate (KIO3) or iodine uptake during food processing is available. Therefore, the influence of cooking on the iodine content of potatoes, pasta, and rice having different size, varieties or composition was investigated. Commonly used cooking procedures were applied, using KIO3-enriched table salt in the cooking water. After iodine extraction with 0.5% NH3 iodine content was measured by ICP-MS. All products showed an increase in iodine content. Waxy potatoes, especially cut in small pieces, and egg pasta showed the highest iodine uptake. Based on the results, the use of KIO3-enriched salt for cooking is recommended to enhance iodine supply.

In liquid foods, various given physical properties affect simultaneously the inactivation of microorganisms by UV-C treatment. Here, the effect of absorption, turbidity and viscosity on the efficiency of UV-C inactivation in a coiled tube reactor was investigated. Model solutions with E. coli DH5α as biodosimeter were chosen. The Weibull fit was suitable to describe the inactivation behavior of E. coli DH5α in the liquids. Regarding the physical parameters, the absorption was identified as the main parameter affecting the inactivation performance. A considerably lower 5D value was observed for the inactivation kinetic at the highest concentration of cellulose particles compared to the absorptive liquids, indicating a minor effect of turbidity on the reduction rate. However, an underperformance of mixing caused by the high viscosity of 10 mPas was observed in absorptive liquids (40 cm- 1). In addition, the inactivation behavior of E. coli DH5α in juices was compared to the reduction in corresponding model juice. It was shown, that inactivation kinetics in model juice can provide first indications for the inactivation behavior of microorganisms in real juices.

Polymeric nanoparticles have been developed for several applications, among them as carrier system of pesticides. However, few studies have investigated the fate of these materials in the environment in relation to colloidal stability and toxicity. In nature, humic substances are the main agents responsible for complexation with metals and organic compounds, as well as responsible for the dynamics of these nanoparticles in aquatic and terrestrial environments. In this context, the evaluation of the influence of aquatic humic substances (AHS) on the colloidal stability and toxicity of polymeric nanoparticles of chitosan/tripolyphosphate with or without paraquat was performed. In this study, the nanoparticles were prepared by the ionic gelation method and characterized by size distribution measurements (DLS and NTA), zeta potential, infrared and fluorescence spectroscopy. Allium cepa genotoxicity studies and ecotoxicity assays with the alga Pseudokirchneriella subcapitata were used to investigate the effect of aquatic humic substances (AHS) on the toxicity of this delivery system. No changes were observed in the physical–chemical stability of the nanoparticles due to the presence of AHS using DLS and NTA techniques. However some evidence of interaction between the nanoparticles and AHS was observed by infrared and fluorescence spectroscopies. The ecotoxicity and genotoxicity assays showed that humic substances can decrease the toxic effects of nanoparticles containing paraquat. These results are interesting because they are important for understanding the interaction of these nanostructured carrier systems with species present in aquatic ecosystems such as humic substances, and in this way, opening new perspectives for studies on the dynamics of these carrier systems in the ecosystem.

In order to minimize quality losses due to enzymatic browning and spoilage reactions during the storage, the effect of a flow through UV-C and UV-B technology on the activity of polyphenol oxidase (PPO) as well as on the shelf life of apple and grape juices was investigated. The absorption of soluble compounds led to smaller effects of UV-C energy on PPO activity in juice than in buffer. Moreover, the pumping and the flow conditions in the coiled tube reactor had additional effects on the activity of the enzymes studied. In contrast, no effect of UV-B energy on PPO activity could be detected at the applied doses. An up to 2 log10 reduction of total aerobic plate count as well as yeasts and molds was reached at a dose of 100.47 kJ L− 1 leading to an extended shelf life of the UV-C treated juice. The high reduction of PPO activity at this dose prevented further browning of apple juice during the refrigerated storage. Industrial relevance Since enzymatic reactions can lead to quality losses during storage, the inhibition of enzyme activity is almost as important as the microbial inactivation in order to prevent spoilage reactions. As shown by the results of this study, browning reactions in juices may be minimized by the UV-C inactivation of polyphenol oxidase providing a product of extended shelf life.

During the processing of meat and meat products the generation of undesirable compounds can occur. Known examples are the generation of substances that can lead to a negative effect on the texture, flavour or colour of products after processing or during storage. Furthermore, thermal processing and smoking have been associated with the generation of or contamination with toxic substances, e.g. polycyclic aromatic hydrocarbons or heterocyclic amines. The introduction of new processing technologies may result in the formation of different undesirable compounds compared to traditional technologies. Some of these changes may be without relevant nutritional or health impact, while others may raise concern. To begin with, an overview on the formation of undesirable process-induced compounds by the traditional processing of meat and the proposed strategies for their reduction is presented. Hereby attention is mainly paid to those compounds which present human health concerns. Later the focus lays on the process-induced modifications occurring in meat as a result of high hydrostatic pressure treatments.

The inactivation performance of a coiled tube reactor was investigated in respect to hydraulic parameters and the impact of flow conditions and absorption on the UV-C energy delivery. Data of the residence time distributions using tracer step response indicate full use of the reactor volume and flow behavior close to ideal plug flow with increasing Reynolds number. Based on the hydraulic characteristics of the coiled tube, the used reactor appears to have an effective design for inactivation. Even though the hydraulic characteristics were similar to plug flow conditions, the attenuation of the UV-C energy delivery due to the presence of absorptive compounds in the liquid remains an influencing parameter on the inactivation performance. In addition, the UV-C dose was evaluated by calculation of the theoretical maximum UV-C energy input and actinometric measurements using iodide/iodate actinometry. Both dose specifications were evaluated for their suitability to describe inactivation kinetics of Escherichia coli ATCC 8739 in clear and absorptive liquid. Since the flow influences the inactivation performance in absorptive liquids, actinometric dose is suitable to describe inactivation kinetics in absorptive liquids.

Freshly squeezed apple juice (cultivar Gala) and commercially available naturally cloudy apple juice were treated with UV-C (254 nm, 0–53 kJ/L) using a commercial UV-C processing unit equipped with a Dean flow reactor. In this study the effect of UV-treatment on enzyme activities, as well as possible cytotoxic and genotoxic effects and furan formation in apple juice were investigated. Even at the highest dose applied (53 kJ/L) no significant effect on the activities of polyphenol oxidase, pectin esterase and polygalacturonase could be determined and residual enzyme activities above 95% were observed in all samples. By raising UV-C irradiation dose to 2.1 kJ/L, the upper limit of practical use, a slight increase in furan concentration from 2.3 to 3.7 μg/kg was observed. However, these concentrations are in the range of commercial, heat-treated juices available on the German market. UV-C treated (10.6 kJ/L) and non-treated apple juice showed no cytotoxic effect in the WST-1 assay when added in concentrations up to 20% (v/v). Furthermore, no difference on DNA strand break formations between treated and non-treated apple juice was observed. Thus, despite a slight increase in the concentration of a potentially genotoxic compound such as furan, UV-C treatment at dosages under investigation did not result in any change in the cytotoxic and genotoxic effects of apple juice on intestinal Caco-2 cells. Industrial relevance Ultraviolet treatment is a promising non-thermal technology for enhancing shelf life of liquid food. While the inactivation of food related microorganisms is well investigated little is known about the effect on compounds like enzymes and in particular the cyto- and genotoxicological potential of UV-C treated products. Our results provide useful information and assistance for regulatory authorities regarding risk and quality assessment of the emerging UV-C technology.

Phytases of different origin were covalently bound onto Fe3O4 magnetic nanoparticles (12 nm). Binding efficiencies of all three phytases were well above 70% relative to the number of aldehyde groups available on the surface of the magnetic nanoparticles. Temperature stability for all three phytases was enhanced as a consequence of immobilisation, whereas pH dependence of enzyme activity was not affected. Maximum catalytic activity of the immobilised phytases was found at 60°C (rye), 65°C (Aspergillus niger) and 70°C (Escherichia albertii). The immobilised enzymes exhibited the same excellent substrate specificities and unique myo-inositol phosphate phosphatase activities as their soluble counterparts. However, the catalytic turnover number dropped drastically for the immobilised phytases. The amount of the desired partially phosphorylated myo-inositol phosphate isomer could be easily controlled by the contact time of substrate solution and immobilised enzymes. The immobilised phytases showed a high operational stability by retaining almost full activity even after fifty uses.

Qualitative and quantitative polymerase chain reaction-based methods to detect genetically modified soy (RoundupReady™ soy) and maize (Bt176 Maximizer™ maize, Bt11 maize, MON810 YieldGard™ corn, T25 LibertyLink™ maize) were applied to processed foods sold commercially in Brazil. From 2000 to 2005, 100 food products containing maize and 100 food products containing soy were analysed every single year. The presence of genetically modified soy increased steadily from 13% in 2000 to 78% in 2005. The number of food products containing genetically modified soy in a proportion above 1.0% on the ingredient level, the threshold for labelling according to Brazilian legislation, increased from 11% in 2000 to 36% in 2005. No clear trend was found within maize containing food products. Eight to eleven percent were shown to consist of material derived from genetically modified maize and 4–6% were found to contain more than 1% of genetically modified maize.

The efficacy of γ-irradiation as a method of decontamination of maize containing Fusarium verticillioides under controlled conditions of relative humidity (RH) (97.5%) and water activity has been studied. Maize grains inoculated with a spore suspension of F. verticillioides were irradiated to 2, 5, and 10 kGy. Thereafter, the irradiated and control samples were analyzed for the presence of fumonisins, their viable cells were counted, and their morphology was investigated by electronic microscopy. It was found possible to decrease the risk of exposure to fumonisins by irradiating maize to 5 or 10 kGy. However, at the dose of 2 kGy, the survived fungi (36%) can produce more fumonisins than the fungi in the control unirradiated samples under the same conditions.

Although legumes provide health benefits, they also contain antinutritional factors like phytate. Excessive amounts of phytate in the diet can lead to mineral deficiencies and phytate should be eliminated by processing. During food processing and digestion, phytate can be dephosphorylated to produce degradation products such as myo-inositol pentakis-, tetrakis-, tris-, bis-, and monophosphates. This paper reports the effect of instantaneous controlled pressure drop (Detente Instantanee Controlee, or DIC) treatment on the phytate content of Lupinus albus and Lupinus mutabilis seeds. The results show the potential of the DIC process for the treatment of lupin seeds: phytate content decreased by 16% (L. albus) and 19% (L. mutabilis) after 1 min of DIC treatment and by up to 55% (L. albus) and 60% (L. mutabilis) after a 7 min treatment.

Samples of legume seeds, cereals and cereal by-products (n = 113) grown in south-western Germany and originating from different cultivars and harvest years were analyzed for phytase activity, total phosphorus (P) and phytate P. Phytase activities determined by means of a direct incubation method were lowest in legume seeds and oats (262–496 U/kg dry matter), intermediate in cereals (except oats) (2323–6016 U/kg DM) and highest in cereal by-products (9241–9945 U/kg DM). However, the application of an extraction procedure for the determination of phytase activities in legume seeds resulted in values below the detection limit of 50 U/kg. On average, about 0.67 of total P in legume seeds, cereals and their by-products is bound to phytate. There was a significant influence (P

Qualitative and quantitative polymerase-chain-reaction-based methods to detect genetically modified (gm) soy (RoundupReadyTM soy) and maize (Bt176 Maximizer maize; Bt11 maize, MON810 Yield Gard corn, T25 LibertyR Link maize) were applied to processed foods sold commercially in Brazil. In total 100 foods containing maize and 100 foods containing soy were analysed in 2000 and again in 2001. In 2000, 13% of the soy containing products and 8% of those containing maize were shown to consist of material derived from the corresponding genetically modified organisms. In five samples of the products containing gm soy 4% of the soy derived material was identified as coming from gm soybeans, whereas in the case of products containing gm maize five samples of the maize derived material were found to contain 4% of gm maize. In 2001, gm soy was found in 21% of the soy containing foods, and gm maize was found in 9% of the maize containing products. Eight samples of the products containing gm soy were shown to contain 4% of gm soy, the corresponding values for gm maize were five samples 4%.

Three soybean varieties were analyzed to evaluate the irradiation influence on the detection of genetic modification. Samples were treated in a 60Co facility at dose levels of 0, 500, 800, and 1000 Gy. The seeds were at first analyzed by Comet Assay as a rapid screening irradiation detection method. Secondly, germination test was performed to detect the viability of irradiated soybeans. Finally, because of its high sensitivity, its specificity and rapidity the polimerase chain reaction was the method applied for genetic modified organism detection. The analysis of DNA by the single technique of microgel electrophoresis of single cells (DNA Comet Assay) showed that DNA damage increased with increasing radiation doses. No negative influence of irradiation on the genetic modification detection was found.

Using a combination of high-performance ion chromatography analysis and kinetic studies, the stereospecificity of myo -inositol hexakisphosphate dephosphorylation by the phytate-degrading enzyme P2 of Escherichia coli was established. High-performance ion chromatography revealed that the phytate-degrading enzyme P2 of E. coli degrades myo -inositol hexakisphosphate by stepwise dephosphorylation via d / l -Ins(1,2,3,4,5)P 5 , d / l -Ins(2,3,4,5)P 4 , d / l -Ins(2,4,5)P 3 or d / l -Ins(1,2,4)P 3 , d / l -Ins(1,2)P 2 or Ins(2,5)P 2 or d / l -Ins(4,5)P 2 to finally Ins(2)P or Ins(5)P. Kinetic parameters for myo -inositol pentakisphosphate hydrolysis by E. coli and wheat phytase, respectively, showed that the myo -inositol pentakisphosphate intermediate produced either by the phytate-degrading enzyme of wheat or E. coli are not identical. The absolute configuration of the myo -inositol pentakisphosphate isomer produced by the E. coli enzyme was determined by taking into consideration that wheat phytase produces predominantly the d -Ins(1,2,3,5,6)P 5 isomer (Lim, P.E., Tate, M.E., 1973. The phytases: II. Properties of phytase fraction F 1 and F 2 from wheat bran and the myo -inositol phosphates produced by fraction F 2 . Biochim. Biophys. Acta 302, 326–328). The data demonstrate that the phytate-degrading enzyme P2 of E. coli dephosphorylates myo -inositol hexakisphosphate in a stereospecific way by sequential removal of phosphate groups via d -Ins(1,2,3,4,5)P 5 , d -Ins(2,3,4,5)P 4 , d -Ins(2,4,5)P 3 , Ins(2,5)P 2 to finally Ins(2)P (notation 6/1/3/4/5).

The Brazilian bean varieties Phaseolus vulgaris L. var. Carioca and Vigna unguiculata (L.) Walp var. Macac∞ ar were irradiated with doses of 0.5, 1.0, 2.5, 5.0 and 10 kGy and subsequently stored at ambient temperature for 6 months. The anti-nutrients phenolic compounds, tannins and phytate were determined to be 0.48 mg g ˇ1 dry basis, 1.8 mg g ˇ1 dry basis and 13.5 mmol g ˇ1 dry basis in the raw non-irradiated Carioca beans and 0.30 mg g ˇ1 dry basis, 0.42 mg g ˇ1 dry basis and 7.5 mmol g ˇ1 dry basis in the raw non-irradiated Macac∞ ar beans. After soaking and cooking a higher content of phenolic compounds and a lower phytate content was observed in both bean varieties. Tannin content was not aAected by soaking and cooking of Carioca beans, but higher after soaking and cooking of Macac∞ ar beans. Using radiation doses relevant for food did not eAect the content of the anti-nutrients under investigation in both bean varieties. # 2000 Elsevier Science Ltd. All rights reserved.

Two phytate-degrading enzymes (myo -inositol hexakisphosphate phosphohydrolase) have been purified from 4-day-old barley seedlings. One phytase (P2) was identified as a constitutive enzyme, whereas the other one (P1) was induced during germination. Both phytases were successfully separated from the major acid phosphatases. The molecular masses of the native monomeric enzymes were estimated to be about 67 kDa. Both phytate-degrading enzymes belong to the acidic phytases. They exhibit a single pH-optimum at 5·0 (P1) and 6·0 (P2), respectively. Optimal temperature for the degradation of phytate was found at 45 °C (P1) and 55 °C (P2), respectively. Kinetic parameters for the hydrolysis of Na-phytate are KM72 μm, kcat136 s−1(P1) and KM190 μm, kcat43 s−1(P2) at 35 °C and optimal pH. The barley phytases exhibit a broad affinity for various phosphorylated compounds and hydrolyse phytate in a step-wise manner. With both phytases, the first hydrolysis product was identified as D/L-Ins(1,2,3,4,5) P5

A cytoplasmatic phytase was purified about 410-fold to apparent homogeneity with a recovery of 28%. The enzyme is induceable under carbon limitation in the presence of phytate. It behaves as a monomeric protein of a molecular mass of about 40 kDa. The phytase is rather specific for phytate and exhibits optimal conditions for phytate degradation at pH 5.0 and 58 degrees C. Kinetic parameters for the hydrolysis of Na phytate are KM 300 microM and kcat 180 s-1 at 35 degrees C and pH 5.0. Phytate is hydrolyzed in a stepwise manner; the penta- and tetrakisphosphate were identified as I(1,2,4,5,6)P5 and I(1,2,5,6)P4. Consequently, this enzyme is a 3-phytase (EC 3.1.3.8).

Model systems for investigating the influence of the food matrix and depth of processing on detection limits for foods deriving from genetic engineering were established using the phytase-encoding gene ofEscherichia coliATCC 33965. For detection the polymerase chain reaction was applied directly to DNA extracted from foods based on cereals.E. colicells andE. coliDNA were added to musli, rolled oats, and rye flour in concentrations of 1010to 102CFU and 10 mg to 10 pg per gram, respectively. After soaking of the food samples in water or yoghurt, detection limits were determined to be 103to 104CFU and 10 to 100 pg by specific DNA hybridization. After sourdough fermentation of rye flour a hybridization signal was observed only with rather highE. coliconcentrations (>1010CFU), whereas detection was impossible in ready-baked breads.