Tenderization of Beef Semitendinosus Muscle by Pulsed Electric Field Treatment with a Direct Contact Chamber and Its Impact on Proteolysis and Physicochemical Properties.

In this study, the effects of pulse electric field (PEF) treatment on the tenderization of beef semitendinosus muscle were investigated. An adjustable PEF chamber was designed to make direct contact with the surface of the beef sample without water as the PEF-transmitting medium. PEF treatment was conducted with electric field strengths between 0.5 and 2.0 kV/cm. The pulse width and pulse number were fixed as 30 µs and 100 pulses, respectively. The impedance spectrum of PEF-treated beef indicated that PEF treatments induced structural changes in beef muscle, and the degree of the structural changes was dependent on the strength of the electric field. Cutting force, hardness, and chewiness were significantly decreased at 2.0 kV/cm (35, 37, and 34%, respectively) (p < 0.05). Troponin-T was more degraded by PEF treatment at 2.0 kV/cm intensity (being degraded by 90%). The fresh quality factors such as color and lipid oxidation were retained under a certain level of PEF intensity (1.0 kV/cm). These findings suggest that PEF treatment could tenderize beef texture while retaining its fresh quality.

Tailoring Physical and Sensory Properties of Tofu by the Addition of Jet-Milled, Superfine, Defatted Soybean Flour.

The use of defatted soybean flour (DSF) in food as a source of dietary fiber has been limited due to its rough texture and bitter taste. Our previous work indicates that superfine DSF prepared by jet milling could overcome these problems, as it positively affected physical and sensory properties. Therefore, differently sized DSFs were incorporated in tofu, and their impacts on physical and sensory properties were investigated in this study. Coarse DSF (Dv50 = 341.0 µm), fine DSF (Dv50 = 105.3 µm), and superfine DSF (Dv50 = 5.1 µm) were prepared by conventional sifting and jet milling. Tofu was made with a 5% addition of differently sized DSFs and without DSF (control tofu). The quality of tofu was evaluated by scanning electron microscopy, color measurement, texture profile analysis, and quantitative descriptive analysis. The tofu made with coarse and fine DSF showed negative changes in its physical and organoleptic qualities, such as reduced yields, a less pure color, a harder texture, and a rougher mouthfeel. However, the tofu made with superfine DSF showed only minimal changes in its qualities compared to the control. Therefore, superfine DSF is a promising fiber supplement that does not change the physical and sensory properties in the making of high-quality tofu.

Effects of Jet-Milled Defatted Soy Flour on the Physicochemical and Sensorial Properties of Hamburger Patties.

We investigated the physicochemical and sensorial properties of hamburger patties made with three different defatted soybean flour (DSF) preparations which differed in particle size. Coarse (Dv50=259.3±0.6 µm), fine (Dv50=91.5±0.5 µm), and superfine (Dv50=3.7±0.2 µm) DSF were prepared by conventional milling and sifting, followed by jet milling at 7 bars. Hamburger patties containing 5% of each DSF were prepared for a property analysis. The hamburger patties made with 5% superfine DSF showed the lowest cooking loss among the treatment groups (p<0.05). The patties with superfine DSF also retained the texture profile values of the control patties in terms of hardness, gumminess, springiness, and chewiness, while the addition of coarse and fine DSF increased the hardness and chewiness significantly (p<0.05). The sensorial results of quantitative descriptive analysis (QDA) indicate that the patties containing superfine DSF were softer and tenderer than the controls (p<0.05). Although the overall acceptability of the patties made with coarse and fine DSF was poor, the overall acceptability of the superfine DSF patty was the same as that of the control patty. These results suggest that superfine DSF is an excellent food material that can supply dietary fiber, while maintaining the physical characteristics and texture of hamburger patty.

Corpus callosum atrophy in Wernicke's encephalopathy.

BACKGROUND AND PURPOSE: Neuropathologic changes in Wernicke's encephalopathy (WE) involve variable brain structures. Corpus callosum involvement in WE, however, is largely unknown. The authors investigated the degree and the pattern of corpus callosum changes in WE according to the etiologies. METHODS: Nineteen patients with WE (between 34 and 81 years) and 19 age- and sex-matched control participants were included. The total cross-sectional callosal area and 5 callosal subregions (C1-C5) were measured by tracing outer margins in the midsagittal sections. Subregions were determined by placing radial dividers with 10 rays. The pixel numbers for corpus callosums were calculated, and the values obtained were adjusted for head size variations. RESULTS: The causes of WE were alcoholism (10), intestinal surgery (5), anorexia (3), and hyperemesis gravidarum (1). The mean size of the total corpus callosum was significantly reduced in alcoholic WE (P< .001; 527.8 +/- 70.8 mm2 for alcoholic WE; 664.6 +/- 58.1 mm2 for the corresponding controls), but not in nonalcoholic WE. In subregion analysis, prefrontal callosum (C2) atrophy was the most prominent in alcoholic WE. In contrast, only splenium (C5) was atrophied in nonalcoholic WE. The degree of atrophy did not change throughout the follow-up period (mean 5.3 weeks). CONCLUSION: This study suggests that the extent and location of corpus callosum atrophy differs between alcoholic WE and nonalcoholic WE, implying separate contribution of alcohol neurotoxicity and nutritional deficiency.

P53 mediates ceramide-induced apoptosis in SKN-SH cells.

Ceramide induces apoptotic cell death in a dose- and time-dependent manner in neuroblastoma SKN-SH cells. Pretreatment with caspase inhibitors blocks cell death, suggesting that a set of caspase activities including caspase 1, as well as caspase 3, are involved in ceramide-induced apoptosis in SKN-SH cells. Treatment with a caspase inhibitor 3 h after ceramide addition did not inhibit cell death, although caspase activity was substantially reduced. Ceramide-induced apoptosis is accompanied by accumulation of p53 followed by an increase of Bax and decrease of Bcl-2 levels. Inhibition of p53 expression with p53 antisense oligonucleotides inhibits apoptosis and prevents the increase in Bax and decrease in Bcl-2. Furthermore, pretreatment with p53 antisense oligonucleotides markedly inhibits the induction of caspase activity. These results suggest that p53 regulates the ratio Bcl-2/Bax and the expression/activation of caspases during ceramide-induced apoptosis in SKN-SH cells. Caspase inhibition did not alter the expression of p53, Bcl-2 and Bax. Thus ceramide-induced reduction in the Bcl-2/Bax ratio, increase in caspase activity, and apoptosis is dependent upon increases in cellular p53 levels which play a critical role in the regulation of apoptotic cell death.