Superhydrophobic surfaces with silane‐treated diatomaceous earth/resin systems

Superhydrophobic coatings were prepared using fluorosilane‐treated diatomaceous earth (DE) with either polyurethane or epoxy binders. The surface wettability and morphology of the films were analyzed using contact angle measurements and scanning electron microscopy (SEM), respectively. The water contact angles were studied as a function of the fluorocarbon fraction on DE and the particle loadings of treated DE in the coating. The contact angles exceeded 150° for coatings with at least 0.02 fluorocarbon fraction (mass of fluorosilane/mass of particle) on the DE and with 0.2 particle loadings (mass of treated particles/mass of coating). The water contact angles of the surfaces were dependent on the nature of the binder below 0.2 particle loadings of the superhydrophobic DE particles, but were independent of the binder type after attaining superhydrophobicity. The results were consistent with the superhydrophobicity resulting from the migration of the superhydrophobic DE moving to and covering the surfaces completely. It was also shown that the treatment with fluorosilanes restricted the pores in DE and reduces the specific surface area of the material. However, these changes had effectively no effect on the superhydrophobicity of the coatings. The results of this work clearly identify some important considerations relative to producing superhydrophobic coatings from inexpensive diatomaceous earth. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44072.     

Effect of cycling frequency and self‐heating on fatigue behavior of reinforced and unreinforced thermoplastic polymers

An experimental study was conducted to evaluate the effect of frequency and self‐heating on fatigue behavior of two unreinforced and two short glass fiber reinforced thermoplastic polymers. Load‐controlled fatigue tests were conducted under fully reversed (R = ?1) and R = 0.1 conditions with specimens loaded in either longitudinal or transverse direction to the mold flow direction. Effect of frequency on fatigue life was evaluated at 23 and 125°C and for a range of frequencies between 0.063 and 20 Hz. Incremental step frequency tests were also performed at different stress ratios and stress levels. Surface temperature rise was found to be material, frequency, and stress level dependent. Three energy‐based models were applied to the incremental step frequency data and relationships were developed for each material to estimate surface temperature rise as a function of test frequency and stress level. Relationships were also developed to assess critical frequency for the unreinforced thermoplastics at a given stress level above which surface temperature does not stabilize. POLYM. COMPOS., 55:2355–2367, 2015. © 2015 Society of Plastics Engineers     

Design,characterization and ex vivo evaluation of chitosan film integrating of insulin nanoparticles composed of thiolated chitosan derivative for buccal delivery of insulin

The purpose of this study is to optimize and characterize of chitosan buccal film for delivery of insulin nanoparticles that were prepared from thiolated dimethyl ethyl chitosan (DMEC-Cys). Insulin nanoparticles composed of chitosan and dimethyl ethyl chitosan (DMEC) were also prepared as control groups. The release of insulin from nanoparticles was studied in vitro in phosphate buffer solution (PBS) pH 7.4. Optimization of chitosan buccal films has been carried out by central composite design (CCD) response surface methodology. Independent variables were different amounts of chitosan and glycerol as mucoadhesive polymer and plasticizer, respectively. Tensile strength and bioadhesion force were considered as dependent variables. Ex vivo study was performed on excised rabbit buccal mucosa. Optimized insulin nanoparticles were obtained with acceptable physicochemical properties. In vitro release profile of insulin nanoparticles revealed that the highest solubility of nanoparticles in aqueous media is related to DMEC-Cys nanoparticles. CCD showed that optimized buccal film containing 4% chitosan and 10% glycerol has 5.81?kg/mm² tensile strength and 2.47?N bioadhesion forces. Results of ex vivo study demonstrated that permeation of insulin nanoparticles through rabbit buccal mucosa is 17.1, 67.89 and 97.18% for chitosan, DMEC and DMEC-Cys nanoparticles, respectively. Thus, this study suggests that DMEC-Cys can act as a potential enhancer for buccal delivery of insulin.     

Development of an efficient stabiliser mixture for physical stability of nonfat unfizzy doogh

The effects of locust bean, carboxymethyl cellulose, a mixture of locust bean and carboxymethyl cellulose and Persian gum on different properties of nonfat doogh were studied over a period of 28 days. The results showed that samples containing a mixture of locust bean and carboxymethyl cellulose had the highest stability. Furthermore, the rheological behaviour of the doogh changed from Newtonian to pseudoplastic. Better sensory acceptability was shown for the treatments containing a mixture of locust bean gum and carboxymethyl cellulose. In general, it was shown that a mixture of locust bean and carboxymethyl cellulose could be of practical use in the industrial production of nonfat doogh.     

Production of angiotensin-converting enzyme inhibitory peptides in Iranian ultrafiltered white cheese prepared with Lactobacillus brevis KX572382

In this study, ultrafiltered (UF) Iranian white cheese made with adjunct cultures including six Lactobacillus isolates (Lactobacillus brevis, L. casei and L. plantarum) from traditional Iranian Motal cheese. The peptide extract (<5 kDa) of cheese samples were assessed for angiotensin-converting enzyme (ACE)-inhibitory activity during ripening (5 °C). Among the strains used, L. brevis KX572382 (M8) was selected because of the greater increase in (ACE)-inhibitory activity in the cheese (P < 0.05). The highest activity of M8 extract was observed on the 28th (71.72%) day of ripening (P < 0.05). Proteolytic activity assessment and RP-HPLC peptide profile of M8 water-soluble extracts (WSEs) indicated the effect of M8 on further protein degradation due to secondary proteolysis. A total of 7 different peptide sequences, previously known in the literature for their ACE-inhibitory activity, were tentatively identified by LC/ESI-MS in 28-day M8 peptide extract. Although the effect of M8 on pH and the proteolysis development in cheese was significant, no adverse effect was observed on the sensory properties. In conclusion, M8 strain can enhance the functional properties of Iranian UF white cheese.     

Comparative effect of probiotic and paraprobiotic addition on rheological and sensory properties of yoghurt

Yoghurt was produced using killed cells of Lactobacillus acidophilus ATCCSD 5221 and Bifidobacterium animalis subsp. lactis BB‐12. The rheological and sensory properties of the yoghurt were investigated at the end of the fermentation. The results revealed that the samples made with killed cells gave the lowest storage modulus, loss modulus, stress crossover point and loss tangent. The frequency‐sweep of yoghurt samples containing paraprobiotics added before fermentation showed the highest correlation coefficient. In the case of sensory assessment, significant differences were indicated among treatments. Adding killed cells of B. animalis subsp. lactis BB‐12 before fermentation produced yoghurt with the highest total score, whereas samples containing killed cells of L. acidophilus ATCCSD 5221 and B. animalis subsp. lactis BB‐12 added before fermentation exhibited the lowest total score.     

Production of propionic acid in a fermented dairy beverage

A dairy beverage containing propionic acid was produced using the adjunct starter cultures with Lactobacillus acidophilus and Propionibacterium freudenreichii ssp. shermanii. The impacts of temperature (30, 35 and 40 °C) and inoculation ratio (1:2, 1:4 and 1:8) on propionic acid production and viability of micro‐organisms were studied. The incubation temperature had a significant adverse (P < 0.05) effect on the viability of P. freudenreichii and propionic acid production. Maximum amount of produced propionic acid (in 1:4–30 °C treatment) was 0.77%w/w. P. freudenreichii and L. acidophilus counts remained high (9 × 10⁶ and 1.5 × 10⁶ cfu/mL, respectively) after cold storage.     

Sheep Milk: Physicochemical Characteristics and Relevance for Functional Food Development

Sheep milk has a high nutritional value and high concentrations of proteins, fats, minerals, and vitamins, as compared to the milks of other domestic species. The physicochemical and nutritional characteristics of sheep milk can be advantageous for the manufacture of products containing prebiotic ingredients and/or probiotic bacteria, which are major categories in the functional food market. Following this technological trend, this review will address the characteristics and advantages of sheep milk as a potentially functional food, as well as the development of sheep milk dairy products containing prebiotics and/or probiotics.     

Application of Liposomes in Some Dairy Products

The application of liposomes as potential carriers to deliver food components is considerably an innovative technology. While the application of liposome technology has been very limited to date, researches indicating the potential of liposomes for improving the flavor of ripened cheese using accelerated methods, the targeted delivery of functional food ingredients, the synergistic delivery of ascorbic acid and tocopherols for promoting antioxidant activity in foods, and the stabilization of minerals (such as iron) in milk have been performed. In the food industry, liposomes and nanoliposomes have been employed to encapsulate flavoring and nutritive agents, and also, they have been suitable candidates to deliver antimicrobials. In this paper, application of lipase, proteinase, nisin, and flavor-containing liposomes in products during the processing (such as cheese maturity) as well as the application of liposomes-encapsulated micronutrients (such as iron) in milk are reviewed.