Effect of ethephon on antioxidant enzymes and diosgenin production in seedlings of Trigonella foenum-graecum

To study the effect of ethylene on growth, diosgenin production and activities of the two antioxidant enzymes catalase and peroxidase, the seedlings of Trigonella foenum-graecum were treated with different concentrations of ethephon (as ethylene generating agent). The fresh weight and the length of seedlings decreased significantly and the dry weight of seedlings increased with increase in concentration of ethephon. At 100 mg/l concentration of ethephon, enzyme activities and diosgenin content decreased significantly. Subsequently, enzyme activities and diosgenin content increased with increase in concentration of ethephon. But diosgenin content did not increase over that of the control. The results suggest that although there is a relation between ethephon concentration, ethephon-induced catalase and peroxidase activities and diosgenin content, ethylene is not required for induction of diosgenin content in T. foenum-graecum seedlings.     

Phase transition in potato starch–water system I. Starch gelatinization at high moisture level

Optical microscopy, micro-calorimetry (Calvet), FTIR spectroscopy and X-ray diffraction were used to study thermal phase transitions in potato starch–water systems at high moisture level (66–82%). Phase transition in potato starch–water systems depended on the moisture content of the system. At higher moisture contents (e.g. >66%), a first-order transition was observed at about 65 °C, which is associated with gelatinization of starch. The transition was cooperative, involving swelling of starch granules with loss of birefringence and crystallinity. Alteration in the secondary structure and conformation of starch is suggested by the changes around 1020 cm⁻¹ (mainly C–O–H bond vibration) in FTIR spectroscopy. The effect of cultivar, fertilization regime and genetic transformation and storage period on the phase transition behavior of potato starch–water system was also examined.     

Variation in antioxidant enzyme activities and nonenzyme components among cultivars of rabbiteye blueberries (Vaccinium ashei Reade) and V. ashei derivatives

Fruit from 42 blueberry (Vaccinium species) cultivars, including 36 rabbiteye cultivars (Vaccinium ashei Reade), 3 V. ashei hybrid derivatives and 3 northern highbush (V. corymbosum L.) standards, were evaluated for antioxidant activities (AA), levels of antioxidant enzymes [catalase (CAT), ascorbate peroxidase (AsA-POD), glutathione reductase (GR), glutathione peroxidase (GSH-POD), superoxide dismutase (SOD), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDAR) and guaiacol peroxidase (G-POD)], and antioxidant nonenzyme components [ascorbic acid (ASA) and glutathione (GSH)]. The results of this study showed that cultivars had varying levels of AA, a wide range of antioxidant enzyme activities and various amounts of nonenzyme components. The correlations between AA and all of the enzyme activities or nonenzyme components were positive and high in the 42 cultivars tested in this study. The correlation (R²) values between AA and CAT, SOD, DHAR, MDAR, GSH-POD, GR, G-POD and AsA-POD were 0.91, 0.91, 0.91, 0.91, 0.90, 0.90, 0.90, and 0.90, respectively. The correlations between AA and ASA and GSH were 0.94 and 0.92, respectively. Among all 42 cultivars, ‘Early May’ had the highest activities of the AA, AsA-POD, G-POD, DHAR and MDAR and the highest amounts of ASA and GSH, whereas ‘Elliott’ had the highest levels of GR, GSH and SOD.     

Profiles,antioxidative and ACE inhibitory activity of peptides released from fermented buttermilk before and after simulated gastrointestinal digestion

Bioactive peptides, released from buttermilk by fermentation and/or gastrointestinal proteases, may have health promoting effects. Thus, a comprehensive analysis of the peptide fraction of fermented buttermilk, before and after different phases of simulated gastrointestinal digestion, was performed using ultra high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UHPLC-ESI-MS/MS). Results showed that digestion simulation substantially changed the peptide profile of fermented buttermilk. A total of 81, 120 and 46 peptides were identified in fermented buttermilk, its gastric and intestinal digests, respectively. These peptides released mostly from β-casein followed by αs1-casein, κ-casein and β-lactoglobulin. In addition, 14 peptides released from milk fat globule membrane proteins (lactadherin, butyrophilin and GlyCAM-1). Bioactivity, mainly angiotensin converting enzyme (ACE) inhibitory activity, has been reported before for only 54 of the detected peptides. Radical scavenging, ferric reducing and ACE inhibitory activities of fermented buttermilk peptides increased significantly after digestion, indicating promotion in fermented buttermilk-peptide bioactivity by gastrointestinal digestion.     

Changes in the physicochemical,structural and emulsifying properties of chicken myofibrillar protein via microfluidization

Microfluidization is a novel and effective technology to improve the properties of myofibrillar protein. The effects of microfluidization with varying pressures (0–120 MPa) on the physicochemical, structural and emulsifying properties of chicken myofibrillar protein (CMP) were studied. Microfluidization treatment remarkably increased the absolute ζ-potential, contact angle, solubility, emulsifying ability and emulsifying stability of CMP. Simultaneously, the turbidity of CMP decreased. After microfluidization treatment, more α-helix structures were transformed into disordered structures, more hydrophobic and negatively charged groups were exposed, leading to improvements in CMP properties. After 90 MPa treatment, the absolute ζ-potential, storage modulus, loss modulus and dynamic apparent viscosity of CMP-camellia oil emulsion reached the maximum values. The hydrophobic interaction between CMP and camellia oil induced CMP to expose more hydrophobic and negatively charged groups, leading to the improved emulsifying properties of CMP. Our results demonstrate that microfluidization treatment has great potential to improve the product qualities of emulsion-type meat products.     

Electrospun poly(vinyl alcohol)/permutite fibrous film loaded with cinnamaldehyde for active food packaging

Electrospun ultra‐fine poly(vinyl alcohol)/permutite fibrous film loaded with cinnamaldehyde essential oil was successfully fabricated.The morphology of fibrous filmswas characterized by scanning electron microscopy (SEM) and atomic force microscope (AFM). The fibrous film exhibited microstructure features with high porosity with the pore size distributed ranging from 1.7 nm to 56.7 nm. And the root‐mean‐squared roughness of fibers lifted to 546.5 nm when the addition of cinnamaldehyde essential oil (CEO) reached 0.25 mL. Attenuated total reflectance‐fourier transform infrared (ATR‐FTIR) spectroscopyconfirmed the existence of CEO in fibrous films and revealed physical interaction rather than chemical interactions existing between the film matrix and CEO. Endothermic peaks presented in differential scanning calorimetry (DSC) profile were probably rooted from existed mesoporous adsorption between the highly porous film matrix and CEO. Furthermore, the PVA/permutite/CEO fibrous film prolonged the shelf life of strawberries, confirming that the PVA/permutite/CEO fibrous film may be of interest for the development of active food packaging. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46117.     

Long term stability of silicon roughness standards

In 1986 the roughness reference standards made of silicon were produced at the Laboratory for Precise Measurements of Length (LFSB), which is now a part of Croatian Metrology Institute (HMI) designated as HMI/FSB-LPMD. At that time, roughness standards were commonly made either from steel or glass.After 3 decades of use it was decided to conduct a research of metrological features on two silicon roughness standards which were continuously used as primary standards for roughness in Croatia.The analysis is based on measurement results of roughness parameters (Ra, Rz and RSm) from calibration certificates provided by several national metrology institutes.Statistical consistency is checked with Birge ratio test, and En values are calculated in order to check if significant change of roughness parameters over the years can be determined.     

Application of electrolyzed oxidizing water in production of radish sprouts to reduce natural microbiota

The objective of this study was to determine the efficacy of electrolyzed oxidizing (EO) water in reducing natural microbiota on radish seed and sprout during seed soaking and sprouting. EO water with different available chlorine concentrations (ACC, 15, 20, 28, 33 and 40 mg/L) and different pH (2.5, 3.5, 4.5, 5.5 and 6.5) were used to soak radish seeds for 12 h and the surviving population of total aerobic bacteria, yeast and mold, and germination rate were determined. On the other hand, EO water with ACC of 30 and 50 mg/L was applied to spray sprouts during seed sprouting and the antimicrobial efficacy of EO water, as well as length, gross weight and dry weight of sprout were evaluated. The results showed that the population of natural microbiota decreased with increasing ACC of EO water, while no significant difference was observed among EO waters with different pH levels that were applied while soaking the seeds. EO water with higher ACC and lower pH slightly reduced the germination percentage of radish seed during seed soaking. EO waters with ACC of 30 and 50 mg/L sprayed during seed sprouting resulted in 1.39 and 1.58 log reductions of total aerobic bacteria, yeast and mold, respectively, and improved the length, gross weight and dry weight of the sprouts. Therefore, EO water with low ACC and near neutral pH could be used to soak seeds and water sprouts throughout seed germination and sprouting to control the population of natural microbiota on seeds and sprouts.