THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

The Design and Analysis of Experiments

An introduction to heat transfer

Endospores of Bacillus spp., especially Bacillus subtilis, have served as experimental models for exploring the molecular mechanisms underlying the incredible longevity of spores and their resistance to environmental insults. In this review we summarize the molecular laboratory model of spore resistance mechanisms and attempt to use the model as a basis for exploration of the resistance of spores to environmental extremes both on Earth and during postulated interplanetary transfer through space as a result of natural impact processes.

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Resistance of Bacillus endospores to extreme terrestrial and extraterrestrial environments.

Pectin is an important polysaccharide with applications in foods, Pharmaceuticals, and a number of other industries. Its importance in the food sector lies in its ability to form gel in the presence of Ca2+ ions or a solute at low pH. Although the exact mechanism of gel formation is not clear, significant progress has been made in this direction. Depending on the pectin, coordinate bonding with Ca2+ ions or hydrogen bonding and hydrophobic interactions are involved in gel formation. In low‐methoxyl pectin, gelation results from ionic linkage via calcium bridges between two carboxyl groups belonging to two different chains in close contact with each other. In high‐methoxyl pectin, the cross‐linking of pectin molecules involves a combination of hydrogen bonds and hydrophobic interactions between the molecules. A number of factors—pH, presence of other solutes, molecular size, degree of methoxylation, number and arrangement of side chains, and charge density on the molecule— influence the gelation o...

Chemistry and uses of pectin--a review.

Astaxanthin is a carotenoid widely used in salmonid and crustacean aquaculture to provide the pink color characteristic of that species. This application has been well documented for over two decades and is currently the major market driver for the pigment. Additionally, astaxanthin also plays a key role as an intermediary in reproductive processes. Synthetic astaxanthin dominates the world market but recent interest in natural sources of the pigment has increased substantially. Common sources of natural astaxanthin are the green algae Haematococcus pluvialis, the red yeast, Phaffia rhodozyma, as well as crustacean byproducts. Astaxanthin possesses an unusual antioxidant activity which has caused a surge in the nutraceutical market for the encapsulated product. Also, health benefits such as cardiovascular disease prevention, immune system boosting, bioactivity against Helycobacter pylori, and cataract prevention, have been associated with astaxanthin consumption. Research on the health benefits of astaxanthin is very recent and has mostly been performed in vitro or at the pre-clinical level with humans. This paper reviews the current available evidence regarding astaxanthin chemistry and its potential beneficial effects in humans.

Astaxanthin: a review of its chemistry and applications.

Summary The effect of high-pressure (HP) treatment (100–400 MPa for 15 or 30 min at 20 � C) on the rheological characteristics and colour of fresh and canned mango pulps was evaluated. Differences were observed in the rheological behaviour of fresh and canned mango pulps treated with HP. Shear stress–shear rate data of pulps were well described by the Herschel– Bulkley model. The consistency index (K) of fresh pulp increased with pressure level from 100 to 200 MPa while a steady decrease was noticed for canned pulp. For fresh pulp the flow behaviour index decreased with pressure treatment whereas an increasing trend was observed with canned pulp. Storage and loss moduli of treated fresh pulp with HP increased linearly with angular frequency up to 200 MPa for a treatment time of 30 min while a steady decreasing trend was found for processed pulp. No significant variation in colour was observed during pressure treatment.

Original article The effect of high pressure treatment on rheological characteristics and colour of mango pulp

Rheological characteristics of 2 commercial brands of stirred yogurt were evaluated using a Haake Rotovisco Model RV 20 with an M-5-Osc measuring head and MV-1 rotor assembly from measured shear stress values under a programmed 3-cycle up- and down-shear rate at 100 s−1/min from 0–500 s−1 (5 min). The upward shear-rate flow behavior of the yogurt samples could be described by a Herschel-Bulkley model while the downward shear-rate curves were essentially linear. Both upward and downward shear rate curves demonstrated progressive structural degradation with repeated shearing. The dependency of rheological parameters on temperature in the range 10–25°C followed both Arrhenius and Turian models.

Rheology of stirred yogurts

Drying is a widespread concept in the food industry, typically employed to convert a surplus crop into a shelf-stable commodity. With advancement of technology, however, there is interest in moving forward from the traditional convective air drying that is most widely used today for grains, both to improve product quality as well as to modernize processes in order to increase throughput and decrease energy costs. In this context, novel techniques for drying and, more recently, microwave-based dehydration techniques have been poised to make an impact commercially. Until now, however, many of these techniques have largely remained in the experimental realm. This article will review recent progress made in microwave-based drying, both benefits and drawbacks, and highlight several technologies with high industrial applicability.

Novel Concepts in Microwave Drying of Foods

Ultrasound-assisted extraction (UAE) technology was used for extracting effective components from pomegranate (Punica granatum L.variety SisheKape-Ferdos) peel (POP). A response surface method was used to investigate the effects of independent process variables (ultrasonic amplitude (power control, UA): 20, 60 and 100%, and ultrasonic exposure time (UET): 5, 10 and 15 min) on the yield (Y) and antioxidant characteristics: total phenolic compounds (TPC), 1,1-diphenyl-2-picrylhydrazyl free radical scavenging (DPPH), ferric reducing-antioxidant power (FRAP), half maximal of radical-scavenging activity (IC50) of aqueous pomegranate peel extract. According to Derringer's desired function approach, the optimal conditions based on both individual and combinations of all process variables were UA 60% and UET 6.2 min, and at this optimum condition, the predicted maximum values of Y, TPC, DPPH, FRAP, and IC50 of the pomegranate peel extract (POPx) were 13.1%, 42.2 mg GA/g, 88.8%, 1824.6 μmol Fe2+/g, and 0.51 mg/mL, respectively. The experimental values were in a good agreement with the predicted values. Also, at optimal conditions, the minimum inhibitory concentration (MIC) of the extract (mean diameter of inhibition zone: 17.7 mm) showed that it had antifungal activities against Aspergillus niger.

Hosahalli S. Ramaswamy

Papers

Original article The effect of high pressure treatment on rheological characteristics and colour of mango pulp

Rheology of stirred yogurts

Novel Concepts in Microwave Drying of Foods

Ultrasound assisted extraction of bioactive compounds from pomegranate (Punica granatum L.) peel

Effect of high-pressure treatment on rheological, thermal and structural changes in Basmati rice flour slurry