High-Pressure processing of kale: effects on the extractability, In vitro bioaccessibility of carotenoids & vitamin e and the lipophilic antioxidant capacity

High pressure processing (HPP) represents a non-thermal preservation technique for the gentle treatment of food products. Information about the impact of HPP on lipophilic food ingredients (e.g., carotenoids, vitamin E) is still limited in more complex matrices such as kale. Both the variation of pressure levels (200–600 MPa) and different holding times (5–40 min) served as HPP parameters. Whereas a slightly decreasing solvent extractability mostly correlated with increasing pressure regimes; the extension of holding times resulted in elevated extract concentrations, particularly at high-pressures up to 600 MPa. Surprisingly, slightly increasing bioaccessibility correlated with both elevated pressures and extended holding times, indicating matrix-dependent processes during in vitro digestion, compared to results of extractability. Moreover, the verification of syringe filters for digest filtration resulted in the highest relative recoveries using cellulose acetate and polyvinylidene difluoride membranes. The α-tocopherol equivalent antioxidant capacity (αTEAC) and oxygen radical antioxidant capacity (ORAC) assays of treated kale samples, chopped larger in size, showed increased antioxidant capacities, regarding elevated pressures and extended holding times. Consequently, one may conclude that HPP was confirmed as a gentle treatment technique for lipophilic micronutrients in kale. Nevertheless, it was indicated that sample pre-treatments could affect HP-related processes in food matrices prior to and possibly after HPP

Aspects of high hydrostatic pressure food processing: Perspectives on technology and food safety

The last two decades saw a steady increase of high hydrostatic pressure (HHP) used for treatment of foods. Although the science of biomaterials exposed to high pressure started more than a century ago, there still seem to be a number of unanswered questions regarding safety of foods processed using HHP. This review gives an overview on historical development and fundamental aspects of HHP, as well as on potential risks associated with HHP food applications based on available literature. Beside the combination of pressure and temperature, as major factors impacting inactivation of vegetative bacterial cells, bacterial endospores, viruses, and parasites, factors, such as food matrix, water content, presence of dissolved substances, and pH value, also have significant influence on their inactivation by pressure. As a result, pressure treatment of foods should be considered for specific food groups and in accordance with their specific chemical and physical properties. The pressure necessary for inactivation of viruses is in many instances slightly lower than that for vegetative bacterial cells; however, data for food relevant human virus types are missing due to the lack of methods for determining their infectivity. Parasites can be inactivated by comparatively lower pressure than vegetative bacterial cells. The degrees to which chemical reactions progress under pressure treatments are different to those of conventional thermal processes, for example, HHP leads to lower amounts of acrylamide and furan. Additionally, the formation of new unknown or unexpected substances has not yet been observed. To date, no safety-relevant chemical changes have been described for foods treated by HHP. Based on existing sensitization to non-HHP-treated food, the allergenic potential of HHP-treated food is more likely to be equivalent to untreated food. Initial findings on changes in packaging materials under HHP have not yet been adequately supported by scientific data

Free Maillard Reaction Products in Milk Reflect Nutritional Intake of Glycated Proteins and Can Be Used to Distinguish “Organic” and “Conventionally” Produced Milk

Using LC-MS/MS and isotopically labeled standard substances, quantitation of free Maillard reaction products (MRPs), namely, <i>N</i>^ε-(carboxymethyl)­lysine (CML), 5-(hydroxymethyl)-1<i>H</i>-pyrrole-2-carbaldehyde (pyrraline, PYR), <i>N</i>^δ-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H), and <i>N</i>^ε-fructosyllysine (FL), in bovine milk was achieved. Considerable variations in the amounts of the individual MRPs were found, most likely as a consequence of the nutritional uptake of glycated proteins. When comparing commercial milk samples labeled as originating from “organic” or “conventional” farming, respectively, significant differences in the content of free PYR (organic milk, 20–300 pmol/mL; conventional milk, 400–1000 pmol/mL) were observed. An analysis of feed samples indicated that rapeseed and sugar beet are the main sources for MRPs in conventional farming. Furthermore, milk of different dairy animals (cow, buffalo, donkey, goat, ewe, mare, camel) as well as for the first time human milk was analyzed for free MRPs. The distribution of their concentrations, with FL and PYR as the most abundant in human milk and with a high individual variability, also points to a nutritional influence. As the components of concentrated feed do not belong to the natural food sources of ruminants and equidae, free MRPs in milk might serve as indicators for an adequate animal feeding in near-natural farming and can be suitable parameters to distinguish between an “organic” and “conventional” production method of milk

Effect of Hay Steaming on the Estimated Precaecal Digestibility of Crude Protein and Selected Amino Acids in Horses

Steaming hay is increasingly used to treat low-quality forage because it was proven to reduce inhalable allergens such as mould spores, bacteria, and airborne dust particles. Preliminary results have shown a substantial loss of precaecal (pc) digestibility (D) of crude protein (CP) and amino acids (AA). For this purpose, six different batches of hay from central Germany were divided into four subsamples, and each one was individually steamed. Native hay and four replicates of each steamed subsample were analysed for CP, AA, neutral detergent insoluble crude protein (NDICP), neutral detergent soluble crude protein (NDSCP) as well as pepsin insoluble CP (piCP). Based on the analytical parameters, pcD of CP, protein solubility (PS), piCP (% CP) and precaecal digestible (pcd) CP and pcdAA contents were calculated. Selected Maillard reaction products (MRP), namely furosine and carboxymethyllysine (CML), were also analysed. Steaming did not affect CP content (native = 69, steamed = 67 g/kg dry matter, DM; p &gt; 0.05), but it had an impact on the insoluble part of CP. Thus, NDICP increased by 57% (native = 27, steamed = 42 g/kg DM; p &lt; 0.05) and piCP by 15% overall (native = 40, steamed = 46% of CP; p &lt; 0.05). This could be a consequence of the heat damage and the associated increase in MRP. The content of furosine rose by 67% (native = 17.6, steamed = 29.4 mg/100 g DM; p &lt; 0.05). The content of CML increased by 120% (native = 5.1, steamed = 11.3 mg/100 g DM; p &lt; 0.05). We chose to analyse these two MRPs because they represent the reaction products with the limiting AA lysine. In contrast, the soluble fractions of CP declined, while PS as a percentage of CP decreased by 38% as a result of the treatment, and NDSCP was reduced by as much as 41% (p &lt; 0.05). In line with this, the steaming process decreased the pcD of CP (native = 56%, steamed = 35%; p &lt; 0.05) and pcdCP (native = 37.9, steamed = 22.5 g/kg DM; p &lt; 0.05), respectively. The same effects were shown for selected AA; e.g., sulphuric AA pcd methionine plus pcd cysteine decreased by 45%, pcd threonine decreased by 41%, and the limited AA pcd lysine decreased by more than 50% (p &lt; 0.05). In conclusion, the high temperatures generated during steaming lead to protein damage and consequently to a reduction in the pcD of CP and essential AA. Nevertheless, steaming successfully reduces viable microorganisms and binds dust particles. Therefore, steamed hay is still a proper and sometimes the only possible roughage for horses suffering from respiratory diseases such as equine asthma. Essentially, horse diets based on steamed hay should be balanced accordingly

No evidence for the involvement of serotonin or the 5-HTTLPR genotype in intertemporal choice in a larger community sample

Background: Serotonin has been implicated in impulsive behaviours such as temporal discounting. While animal studies and theoretical approaches suggest that reduced tonic serotonin levels increase temporal discounting rates and vice versa, evidence from human studies is scarce and inconclusive. Furthermore, an important modulator of serotonin signalling, a genetic variation in the promoter region of the serotonin transporter gene (5-HTTLPR), has not been investigated for temporal discounting so far. Objective: First, the purpose of this study was to test for a significant association between 5-HTTLPR and temporal discounting. Second, we wished to investigate the effect of high/low tonic serotonin levels on intertemporal choice and blood oxygen-level-dependent response, controlling for 5-HTTLPR. Methods: We tested the association of 5-HTTLPR with temporal discounting rates using an intertemporal choice task in 611 individuals. We then manipulated tonic serotonin levels with acute tryptophan interventions (depletion, loading, balanced) in a subsample of 45 short (S)-allele and 45 long (L)/L-allele carriers in a randomised double-blind crossover design using functional magnetic resonance imaging and an intertemporal choice task. Results: Overall, we did not find any effect of serotonin and 5-HTTLPR on temporal discounting rates or the brain networks associated with valuation and cognitive control. Conclusion: Our findings indicate that serotonin may not be directly involved in choices including delays on longer timescales such as days, weeks or months. We speculate that serotonin plays a stronger role in dynamic intertemporal choice tasks where the delays are on a timescale of seconds and hence are therefore directly experienced during the experiment

Aspects of high hydrostatic pressure food processing: Perspectives on technology and food safety

The last two decades saw a steady increase of high hydrostatic pressure (HHP) used for treatment of foods. Although the science of biomaterials exposed to high pressure started more than a century ago, there still seem to be a number of unanswered questions regarding safety of foods processed using HHP. This review gives an overview on historical development and fundamental aspects of HHP, as well as on potential risks associated with HHP food applications based on available literature. Beside the combination of pressure and temperature, as major factors impacting inactivation of vegetative bacterial cells, bacterial endospores, viruses, and parasites, factors, such as food matrix, water content, presence of dissolved substances, and pH value, also have significant influence on their inactivation by pressure. As a result, pressure treatment of foods should be considered for specific food groups and in accordance with their specific chemical and physical properties. The pressure necessary for inactivation of viruses is in many instances slightly lower than that for vegetative bacterial cells; however, data for food relevant human virus types are missing due to the lack of methods for determining their infectivity. Parasites can be inactivated by comparatively lower pressure than vegetative bacterial cells. The degrees to which chemical reactions progress under pressure treatments are different to those of conventional thermal processes, for example, HHP leads to lower amounts of acrylamide and furan. Additionally, the formation of new unknown or unexpected substances has not yet been observed. To date, no safety-relevant chemical changes have been described for foods treated by HHP. Based on existing sensitization to non-HHP-treated food, the allergenic potential of HHP-treated food is more likely to be equivalent to untreated food. Initial findings on changes in packaging materials under HHP have not yet been adequately supported by scientific data