PCR identification of ruminant tissue in raw and heat-treated meat meals

To control the spread of bovine spongiform encephalopathy in cattle through contaminated animal feedstuffs, screening of feed products is essential. We designed five pairs of primers to identify specifically raw and heat-treated tissue from cattle, sheep, goat, deer, and ruminants in general. A forward common primer was designed based on a conserved DNA sequence in the mitochondrial 12S rRNA-tRNA(val)-16S rRNA gene, and reverse primers were designed to hybridize with a species-specific DNA sequence for each species considered. All primers were developed to create a specific PCR product small enough (less than 200 bp) to be suitable for heat-treated material. To evaluate the effect of heat treatment, a severe sterilization condition (133 degrees C at 300 kPa for 20 min) was chosen. Species-specific amplicons were obtained from all types of heat-treated meat meals. Analysis of laboratory-contaminated vegetable meals revealed that the detection limit of the assay was 0.05% for each species analyzed. This PCR-based analysis can be used as a routine method for detecting banned animal-derived ingredients in raw and heat-treated feedstuffs.     

Digestibility and physicochemical properties of granular sweet potato starch as affected by annealing

The effects of annealing on the digestibility, morphology, and physicochemical characteristics of four types of granular sweet potato starches [Yulmi (YM), Yeonwhangmi (YHM), sweet potato starch from Samyang Genex (SSPS), and commercial sweet potato starch (CSPS)] were investigated. Annealing was performed at 55°C and 90% moisture content for 72 h. Morphology, the branched chain distribution of amylopectin, and the X-ray diffraction pattern remained unchanged during the annealing process. The slowly digestible starch content in annealed YM, YHM, and SSPS starches increased, but did not change in annealed CSPS. The gelatinization temperatures increased, but the gelatinization temperature range decreased with annealing. The swelling factor and amylose leaching decreased, while the close packing concentration increased. Rapid Visco Analyser analysis revealed that annealed starches possessed thermal stability and higher pasting temperatures. It is suggested that the enhanced packing arrangement formed during annealing impacts the digestibility and physicochemical properties of sweet potato starches.     

Process development for stabilization of sugarcane juice using response surface methodology

Sugarcane juice is a very popular drink in India and other Asian countries, where sugarcane is an important crop. Since sugarcane juice spoils very quickly and there is a lack of research in this area, no commercialized sugarcane juices are available in India. Here, stabilized sugarcane juice was developed using response surface methodology. Total soluble solids, reducing sugar, total sugar, polyphenol oxidase activity, ascorbic acid, pH, optical density, transmittance, titrable acidity, microbiological properties, and sensory scores of the stabilized juice were evaluated using a Box–Behnken design. The composition was optimized and the sugarcane drink was further processed using blending and hot filling techniques. The processed juice was hot-filled into glass bottles under aseptic conditions. The predicted shelf life of the processed sugarcane juice was 3 months at 18 °C and 6 months at 10 °C.     

Corrosion Behaviors of Zirconia Refractory by CaO–SiO2–MgO–CaF2 Slag

In this work the corrosion behaviors of zirconia refractory (partially MgO-stabilized zirconia) was investigated in CaO–SiO₂–MgO–CaF₂ slag with varying CaF₂ content at 1873 K. To figure out the corrosion mechanism, the characteristics of present slag at high temperature were examined in terms of melting temperature and vaporization behaviors. Corrosion experiment and melting temperature measurement were carried out by heating microscope (HM) and the vaporization phenomenon was investigated by thermo gravimetry–differential scanning calorimetry. After experiment, the corroded interfaces of zirconia refractory by slag were analyzed by scanning electron microscope-energy dispersive spectroscopy and electron probe microanalysis. With an addition of CaF₂, three different layers were formed at the interface of slag and zirconia refractory. Furthermore, the corrosion behaviors of zirconia refractory were found to be continuously accelerated with an increase of CaF₂ which facilitated the dissolution of intermediate compound. On the other hand, melting temperature of CaO–SiO₂–MgO–CaF₂ slag showed no continuous decrease with an increase of CaF₂. Also, considerable vaporization of fluoride gas was occurred in high CaF₂ containing slag during HM experiment which might cause a gradual change of slag composition and also environmental pollution. From the results, present study suggested that a proper amount of CaF₂ should be added when it is used for enhancing refining capacity of slag in order not to cause any severe damage of zirconia-based refractory by slag.     

Effect of hydrophilic and hydrophobic cyclodextrins on the release of encapsulated allyl isothiocyanate (AITC) and their potential application for plastic film extrusion

Allyl isothiocyanate (AITC), a natural pungent flavor from wasabi and horseradish, is well-known antimicrobial agents against foodborne pathogens. However, its highly volatile nature and low thermal stability restrict its application in the food packaging industry. Also, its strong organoleptic characteristics hinder its application at a higher dosage. We encapsulated AITC in β-cyclodextrin (β-CD) and triacetyl-β-CD (TA-β-CD) and evaluated the performance as slow releasing active compounds through low-density polyethylene (LDPE)–cyclodextrins (CDs) matrix. Also, the thermal, optical, mechanical, and barrier properties of two ternary blends, LDPE/β-CD/AITC(L-CDs) and LDPE/TA-β-CD/AITC(L-TACDs), were investigated to compare their compatibility under the plastic extrusion process. During the 15 days of the storage period, L-TACDs maintained more consistent AITC release and a higher concentration than L-CDs. Also, the blending of LDPE and TA-β-CD was more compatible with that of LDPE and β-CD. No significant optical, mechanical, and barrier property changes were observed in LDPE with less than 3% of TA-β-CD while L-CDs showed substantial agglomeration on the ternary blend films and the lower mechanical and barrier properties than pure LDPE. The results indicate that the LDPE films containing TA-β-CD/AITC can be applied as an effective antimicrobial packaging material for food and nonfood applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48137.     

Effect of baicalein and acetone extract of Scutellaria baicalensis on canola oil oxidation

There is an increasing interest in natural antioxidants present in traditional Chinese herbal medicines. The present study examined the antioxidant activity of heane, acetone, and methanol extracts, as well as baicalein purified from the dry roots of Scutellaria baicalensis Georgi (common name: Huangqin), in heated canola oil. Oxygen consumption and decreases in linoleic acid linolenic acid content were monitored in canola oil held at 90–93°C. Among the three extracts, the acetone extract was most effective against oxidation of canola oil, followed by the methanol extract of the dry roots. The antioxidant activity of these three extracts correlated well with their content of baicalein, which provided strong protection to canola oil from oxidation. The antioxidant activity of Huangqin acetone extract was dose-dependent. The acetone extract at 100 ppm or above was even more effective than butylated hydroxytoluene at 200 ppm in protecting canola oil from oxidation. The present results suggest that the acetone extract of these roots should be further explored as a potential source of natural antioxidants for use in the processed foods.     

Single-walled carbon nanotube/silicone rubber composites for compliant electrodes

Single-walled carbon nanotube (SWCNT)/silicone rubber composites that can be used in fabricating compliant electrodes are prepared by spraying a mixed solution of ionic-liquid-based SWCNT gel and silicone rubber onto an elastic substrate. Subsequently, the composites are exposed to nitric acid vapor. Scanning electron microscopy and atomic force microscopy images of the composites show that the SWCNTs are finely dispersed in the polymer matrix due to the addition of the ionic liquid. Doping of the SWCNTs by nitric acid can significantly lower the sheet resistance (R_s) of the composites; samples with 4 wt% of SWCNT content exhibit the lowest R_s value (50 Ω sq^?1). This sheet resistance corresponds to a conductivity value of 63 S cm^?1. In addition, the composites retain a high conductivity after several tensile strains are applied. Stretching the composite sample to 300% of the original length increased the R_s value to 320 Ω sq^?1 (19 S cm^?1). Even after 20th stretch/release/stretch cycle, the conductivity remains constant at a value of 18 S cm^?1. These results provide a scalable route for preparing highly stretchable and conductive SWCNT composites with relatively low SWCNT concentrations.     

High-performance field emission from a carbon nanotube carpet

We have created a field emitter composed of a carbon nanotube (CNT) yarn, which was prepared by direct spinning through chemical vapor deposition and then formed into a carpet structure by tying the yarn to a conductive substrate before cutting it. The structure of the carpet is arranged to induce the tips of the CNT yarn to protrude toward the anode for maximum electron emission. The turn-on field, threshold field, and field enhancement factor of the device are 0.33, 0.48 V/μm, and 19,141, respectively. Extremely low operating electric fields and a high field enhancement factor result from the high density of CNT emitters with high crystallinity, the electrically good contact between the emitters and the substrate, and the effects of the multistage structure. The emission is stable even at a high current density of 2.13 mA/cm², attributed to the strong adhesion between the emitters and the substrate. The emission performance is found to be customizable by adjusting the structure, for example, the CNT pile density. These results are relevant for practical applications, such as large-area flat-panel displays, large-area low-voltage lamps, and X-ray sources.     

Steam reforming of n-hexadecane over noble metal-modified Ni-based catalysts

Steam reforming of n-hexadecane, a main constituent of diesel, over noble metal-modified Ni-based hydrotalcite catalyst was carried out in a temperature range of 700–950 °C, at an atmospheric pressure with space velocity of 10,000–100,000 h⁻¹ and feed molar ratio of H₂O/C = 3.0. The catalysts were prepared by a co-precipitation and dipping methods. The noble metal-modified Ni-based hydrotalcite catalyst displayed higher resistance for the sintering of active metal than the Ni-based hydrotalcite catalyst prepared by the conventional method. It was found that the Rh-modified Ni-based catalysts showed high resistance to the formation of carbon compared to Ni-based catalysts. The results suggest that Rh-modified Ni-based catalyst can be applied for the steam reforming (SR) reaction of diesel.     

Dietary Monounsaturated Fatty Acids but not Saturated Fatty Acids Preserve the Insulin Signaling Pathway via IRS-1/PI3K in Rat Skeletal Muscle

Saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) show different effects on the development of insulin resistance. In this study, we compared the effect of dietary SFA and MUFA on the insulin signaling pathway in the skeletal muscle of a type 2 diabetic animal model. Twenty-nine-week-old male Otsuka Long-Evans Tokushima fatty (OLETF) rats were randomly divided into three groups and fed one of the following diets for 3 weeks; a normal chow diet, an SFA (lard oil) enriched or a MUFA (olive oil) enriched high-fat diet. The vastus lateralis muscle was used for analyses. Insulin tolerance test showed improved insulin sensitivity in rats fed the MUFA diet, as compared to those fed the SFA diet (p < 0.001). The SFA diet reduced IRS-1 expression and phosphorylated PI3K levels in skeletal muscle, as compared with a chow diet (p < 0.001, respectively). On the contrary, muscle IRS-2 expression and phosphorylated ERK1/2 was significantly increased in rats fed the SFA diet (p < 0.001, respectively). Membrane translocation of glucose transporter type 4 decreased in the skeletal muscle of rats fed the SFA diet, as compared to those fed a chow diet (p < 0.001). These changes in insulin signaling pathway in skeletal muscle were not observed in rats fed the MUFA diet. In conclusion, the beneficial effect of dietary MUFA on insulin sensitivity is associated with a conserved IRS-1/PI3K insulin signaling pathway which was altered by dietary SFA.