The paradox of observation and the observation of paradox

Abstract

Achilles cannot overtake a fleeing tortoise because in the interval of time that he takes to get to where the tortoise was, it can move away. But even if it should wait for him Achilles must first reach the half-way mark between them and he cannot do this unless he first reaches the half-way mark to that mark, and so on indefinitely. Against such an infinite conceptual regression he cannot even make a start, and so motion is impossible (Zeno, according to Zippin 1962, p. 10).     

TOXICITY, MUTAGENICITY AND TERATOGENICITY OF BREVIANAMIDE, VIOMELLEIN AND XANTHOMEGNIN; SECONDARY METABOLITES OF PENICILLIUM VIRIDICATUM

The three major secondary metabolites of Penicillium viridicatum, brevianamide, xanthomegnin, and viomellein were tested for mutagenicity by the Salmonella/microsome test and for toxicity and teratogenicity by the chick embryo test. None were mutagenic. Viomellein was mildly toxic and teratogenic, xanthomegnin was the most toxic and was not a teratogen, and brevianamide was not toxic yet was the most teratogenic.     

The role of homogenization in the manufacture of halloumi and mozzarella cheese from recombined milk*

When halloumi and mozzarella cheese are made from normal recombined milk, neither product exhibits the characteristic stretch and melt behaviour of the fresh milk cheeses. The present study demonstrates that this problem may be overcome either by using low homogenization pressures to prepare the recombined milk or by coating the fat in the recombined milk emulsion with phospholipid and homogenizing at the usual pressure. The influence of homogenization of milk on the properties of the cheese is discussed in terms of a polymer network model.     

Canned Salmon Curd Reduced by Use of Polyphosphates

Significant reduction of curd in canned salmon prepared from frozen fish was achieved. Prior to being placed in the can, salmon steaks or pieces were given dips of a few seconds to 2 min in sodium poly-phosphate in concentrations from 5% to saturated. Curd was effectively reduced in canned pink and sockeye salmon prepared from fish in frozen storage for up to a year, to a level at least equivalent to canned salmon prepared from fresh fish. Improvements in flavor and texture were noted. A simple scoring system is presented for evaluating canned salmon based upon visual scoring of curd present on the surface of canned product.     

Application of HPLC for the Determination of PSP Toxins in Shellfish

A high performance liquid chromatographic (HPLC) procedure for determination of the toxins associated with paralytic shellfish poisoning (PSP) is compared to the standard AOAC mouse bioassay method on 100 shellfish samples representing a variety of species. For those samples with toxin content below the detection limit of the bioassay (35 μg saxitoxin (STX)/100g) HPLC analysis indicated a similar low level with a range of <10 to 56 μg STX/100g (n = 60). A correlation coefficient of 0.92 was determined for the 40 samples exhibiting toxicity in the bioassay (i.e., >35 μg STX/100g). Among the advantages of the HPLC method over the bioassay are significantly better sensitivity, greater sample through-put, and ability to determine the levels of each individual PSP toxin.     

Phase Relations and Ordering in the Systems MgO-Y2O3-ZrO2 and CaO-MgO-ZrO2

The phase relations in the systems MgO-Y₂O₃-ZrO₂ and CaO-MgO-ZrO₂ were established at 1220° and 1420°C. The system MgO-Y₂O₃-ZrO₂ possesses a much-larger cubic ZrO₂ solid solution phase field than the system CaO-MgO-ZrO₂ at both temperatures. The ordered δ phase (Zr₃Y₄O₁₂) was found to be stable in the system ZrO₂-Y₂O₃ at 1220°C. Two ordered phases φ₁ (CaZr₄O₉) and φ₂ (Ca₆Zr₁₉O₄₄) were stable at 1220°C in the system ZrO₂-CaO. At 1420°C no ordered phase appears in either system, in agreement with the previously determined temperature limits of the stability for the δ, φ₁, and φ₂ phases. The existence of the compound Mg₃Y_zO₆ could not be confirmed.     

Amorphous carbon anode with controllable pores for rechargeable lithium-ion battery

为满足储能市场对高功率电池的需求,开发兼具高容量和高功率性能的锂离子电池负极材料成为必然趋势。本文通过改变煤基沥青在碳化过程中的空速,考察其对无定形碳材料结构的影响,提高煤基沥青无定形碳材料的电化学性能。应用X射线粉末衍射（XRD）、拉曼（Raman）、N₂吸附-脱附和扫描电镜对所制备的无定形碳材料进行结构表征。通过比容量、库仑效率、倍率、循环性能评判材料的电化学性能。结果表明：可以通过改变气体空速来调控无定形碳材料的孔道和碳层无定形度,实现同步提升容量和倍率性能的效果。当气体空速≥0.5 m/min时,充电容量可达近260 mA·h/g,2C充电容量可达约137 mA·h/g。     

INHIBITORY EFFECT OF ANTHOCYANIN EXTRACT FROM SEED COAT OF BLACK BEAN ON PERICARP BROWNING AND LIPID PEROXIDATION OF LITCHI FRUIT DURING STORAGE

ABSTRACT

Anthocyanins were extracted from seed coats of black beans (Glycine max[L.]) and the inhibitory effects of anthocyanin extract on pericarp browning and lipid peroxidation of litchi fruit were investigated. Litchi fruit were infiltrated for 3 min with 0 (control) or 50 mg/L of anthocyanin extract at a reduced pressure of 53 kPa, then packed in 0.03 mm thick polyethylene bags, and finally stored at 28C for 6 days. Changes in browning index, contents of anthocyanins and total phenol, peroxidase (POD) activity, levels of relative leakage rate and lipid peroxidation, α,α‐diphenyl‐β‐picrylhydrazy (DPPH) radical scavenging activity and reducing power were evaluated. Application of anthocyanin extract from black bean delayed pericarp browning of litchi fruit during storage, which was associated with reduced POD activity and higher contents of anthocyanins and total phenol. Moreover, the anthocyanin extract was found to have a direct inhibition on the POD activity in vitro. Furthermore, application of the anthocyanin extract apparently reduced lipid peroxidation and relatively maintained membrane integrity, which may account for browning inhibition to an extent. Finally, higher DPPH radical scavenging activity and reducing power of the fruits treated with the anthocyanin extract than control fruits possibly benefited in scavenging free radicals and reducing lipid peroxidation. It is, therefore, suggested that inhibited POD activity and reduced lipid peroxidation by the anthocyanin extract from seed coats of black beans were responsible for the inhibition of pericarp browning of litchi fruits.

PRACTICAL APPLICATIONS

Lipid peroxidation is a major cause of quality deterioration of postharvest fruits and vegetables. Some synthetic antioxidants are beneficial in inhibiting lipid peroxidation. However, considering that synthetic antioxidants, such as butylhydroxyanisole and butylated hydroxytoluene (BHT), have potential toxicity, the use of natural extracts to extend the shelf life of postharvest fruits and vegetables is a tendency. In our previous study, it has been found that anthocyanin extract from litchi pericarp has stronger antioxidant activities or free radical scavenging activities than BHT and ascorbic acid ( Duan et al. 2007 ). In this study, the application of anthocyanin extract from seed coat of black soybean showed reduced lipid peroxidation and pericarp browning. It could be used potentially as a postharvest technology for reducing or replacing the use of other chemicals, but it requires further investigation.     

Phytate × Calcium/Zinc Molar Ratios: Are They Predictive of Zinc Bioavailability?

The utility of the phytate/zinc and phytate × calcium/zinc molar ratios for predicting zinc bioavailability from processed soybean foods was investigated. Weight gain and bone zinc accumulation in rats fed various soy protein products were plotted against the calculated molar ratios. The phytate × calcium/zinc ratio was a better predictor of zinc bioavailability in similarly processed products than was the phytate/ zinc ratio. However, in some cases the phytate × calcium/zinc ratio was not effective since some processing procedures apparently altered binding of phytic acid to minerals and other food components.     

Softening of Canned Apricots: A Chelation Hypothesis

Infiltration of apricot (Prunus armeniaca L.), Patterson cultivar fruits, which are susceptible to rapid softening, with calcium chloride before processing resulted in definite firming of the canned apricots. Non-susceptible fruits treated with citrate buffers (pH 3.7) showed dramatic post-process softening. In individual, untreated, early, green fruit, firmness after processing was directly correlated with the bound calcium:citrate ratio. Based on a chelation hypothesis, it was proposed that softening was accelerated when chelators such as organic acid anions removed structural calcium from the cell wall once cell membranes were lysed by heating.