Storage conditions affect quality of noodles with added soy flour and sweet potato

Summary Noodles were prepared from a formulation in which a portion of the flour was replaced with 10% defatted soy flour and sweet potato as 10% flour or 15% puree. Dried noodles were packaged in plastic bags under partial vacuum or air and stored at 4.4 °C or 22–30 °C for 6 months. Colour, β-carotene and sensory characteristics were analyzed at 2-month intervals. Packaging atmosphere had minor effects on colour. Stored noodles became lighter and yellower, and β-carotene decreased, with all changes being greater at 22–30 °C. Storage conditions influenced acceptability scores minimally. Noodles were stored successfully under air with greater quality retention with 4.4 °C storage.     

Flavor and Storage Stability of Potato Chips Fried in Cottonseed and Sunflower Oils and Palm Olein/Sunflower Oil Blends

ABSTRACT: Potato chips fried in cottonseed (CSO) and sunflower (SFO) oils and 20 and 40% palm olein oil (POO):SFO blends were stored at 23 to 25 °C for 0-, 3- and 6-wk in dark (DS) and in 1.5-1.7 footcandles of light (LS). During DS, peroxide values (PV) increased only in chips fried in SFO. In LS, PV increased at lower rates in chips fried in POO blends than in CSO or SFO. Sensory evaluation showed potato chip flavor intensity was similar among oils/blends and unchanged during storage, but intensities of oxidative rancidity and off-flavor increased in chips fried in CSO at 6-wk LS. This off-flavor most likely was due to 1-decyne identified by SPME analysis. Addition of POO to SFO improved the stability of chips as measured by PV without sacrificing potato chip flavor.     

Occurrence of Escherichia coli O157:H7 in diverse farm environments

In the United States, foodborne outbreaks of Escherichia coli O157:H7 illness have often been linked to the consumption of contaminated, undercooked ground beef. However, the occurrence of E. coli O157:H7 has also been reported in other farm animals. The objective of this study was to evaluate the occurrence of E. coli O157:H7 on diverse farm types and from a variety of farm samples. Rectal swabs (n=1686) and environmental samples (n=576) were collected from 16 farms in five states over 24 months and analyzed for the presence of E. coli O157:H7. Overall, E. coli O157:H7 was found in 3.6% of beef cattle, 3.4% of dairy cattle, 0.9% of chicken, 7.5% of turkey, and 8.9% of swine samples. The pathogen was isolated sporadically from each of the environmental sample types. Of particular concern was the isolation of E. coli O157:H7 from fresh feed samples, indicating a potential vector for transmission. The data from this study indicate a high occurrence of E. coli O157:H7 on swine and turkey farms. This unexpected result suggests that more research on the occurrence of E. coli O157:H7 on these types of farms is required in order to better understand potential reservoirs of pathogenic E. coli.     

Mechanically interlocked gold and silver nanoparticles using metallosupramolecular catenane chemistry

We have employed the toolbox of metallosupramolecular chemistry to mechanically interlock gold and silver nanoparticles. A specifically designed PEGthiol-functionalized bis(phenanthroline)copper(I) complex acts to 'catenate' the nanoparticles. The interlocked assemblies were characterised by three complementary techniques: DLS, SERS and TEM.     

Prevalence of Salmonella in diverse environmental farm samples

The development of suitable intervention strategies to control Salmonella populations at the farm level requires reliable data on the occurrence and prevalence of the pathogen. Previous studies on Salmonella prevalence have focused on acquiring data from specific farm types and/or selected regions. The purpose of this study was to evaluate the distribution of this pathogen across a variety of farm types and regions in order to generate comparative data from a diverse group of environmental samples. Farm samples (n = 2,496) were collected quarterly from 18 different farms across five states (Tennessee, North Carolina, Alabama, California, and Washington) over a 24-month period. The participating farms included beef and dairy cattle operations, swine production and farrowing facilities, and poultry farms (both broiler chicken and turkey). The samples were analyzed for the presence of Salmonella by means of the U.S. Food and Drug Administration's Bacteriological Analytical Manual methods optimized for farm samples. Salmonella isolates were characterized by automated riboprinting. Salmonella serovars were recovered from 4.7% of all samples. The majority of positive findings were isolated from swine farms (57.3%). The occurrence of Salmonella was lower on dairy farms (17.9%), poultry farms (16.2%), and beef cattle farms (8.5%). The most commonly isolated serovar was Salmonella Anatum (48.4%), which was isolated notably more frequently than the next most common Salmonella serovars, Arizonae (12.1%) and Javiana (8.8%). The results of this study suggest that significant reservoirs of Salmonella populations still exist on swine production facilities and to a lesser extent in other animal production facilities. Data showed that the surrounding farm environment could be an important source of contamination.     

Evaluation of methods for recovery of Salmonella from dairy cattle, poultry, and swine farms

Current official methods for detection and isolation of Salmonella are mostly designed for foods. The objective of this study was to determine optimal methods for detection and isolation of Salmonella from animal and environmental samples of dairy, poultry, and swine farms. Preenrichment in lactose broth versus direct enrichment (no preenrichment) prior to selective enrichment in Rappaport-Vassiliadis, selenite cystine, and tetrathionate incubated at 35 and 42 degrees C and in four differential/selective plating media (brilliant green, bismuth sulfite, Hektoen enteric, and xylose-lysine-tergitol 4 agar base) were evaluated for their ability to recover Salmonella from artificially contaminated samples. The effects of pH adjustments to samples on Salmonella recovery were determined. A pH adjustment of the enrichment broth to 6.8 +/- 0.2 after addition of samples significantly improved recovery of Salmonella. The most effective medium combinations for isolation of Salmonella from farm samples depended on the type of samples. Generalizations of protocols for recovery of Salmonella from farm samples might result in poor recovery, increased recovery time, and increased sample processing costs.     

Volatile Compounds and Storage Stability of Potato Chips Fried in Mid-Oleic Sunflower Oil

Potato chips fried in mid-oleic sunflower oil were stored in closed containers at ambient temperature (～22°C) either in dark or under fluorescent light for 6 weeks. Lightness and yellowness of chips decreased with storage time. Peroxide values were influenced by storage conditions and time. Sixteen flavor volatiles were positively identified and concentrations of hexanal and 2-furaldehyde increased with storage time. However, t,t,-2,4-decadienal was not affected by storage time. The results indicated that potato chips fried in mid-oleic sunflower oil might retain the desirable fried flavor during 6 weeks of storage in a sealed container in the dark.     

Direct determination of the number-weighted mean radius and polydispersity from dynamic light-scattering data

We compare results for the number-weighted mean radius and polydispersity obtained either by directly fitting number distributions to dynamic light-scattering data or by converting results obtained by fitting intensity-weighted distributions. We find that results from fits using number distributions are angle independent and that converting intensity-weighted distributions is not always reliable, especially when the polydispersity of the sample is large. We compare the results of fitting symmetric and asymmetric distributions, as represented by Gaussian and Schulz distributions, respectively, to data for extruded vesicles and find that the Schulz distribution provides a better estimate of the size distribution for these samples.     

Measurements of sooting tendency in laminar diffusion flames of n-heptane at elevated pressure

This research focuses on the effects of an increasing pressure on the soot formation during combustion of vaporized liquid fuel. Therefore soot formation is measured in a laminar diffusion flame, with n-heptane as fuel, over a range of pressures from 1.0 to 3.0 bar. The soot volume fraction in the diffusion flames has been measured using Laser-Induced Incandescence (LII) calibrated by means of the Line Of Sight Attenuation (LOSA) technique. The values of the calibration factors between LII intensities and soot volume fraction from LOSA are slightly varied for different pressure. The integral soot volume fractions show power law dependence on pressures, being proportional to pⁿ, with n being 3.4 ± 0.3 in the pressure range of 1.0–3.0 bar.     

Comparative Biological Activities Determination of Aqueous Extracts of Hempseed Oil and Hempseed Protein Isolate Production Coproducts

Industrial hempseed is an important agricultural crop with increasing potential for food applications. The objective of this study was to determine the different biological activities of hempseed coproducts after hempseed oil extraction and hempseed protein isolate precipitation. Hempseed oil was extracted by n-hexane and the defatted meal was dried. The hempseed protein isolate was prepared by alkaline pH solubilization followed by isoelectric precipitation. Two coproducts were obtained by freeze drying the precipitate after alkaline solubilization and freeze drying the supernatant after isoelectric precipitation. The coproducts were called hempseed meal after protein isolation (HM-PI) and hempseed supernatant after protein isolation (HS-PI). The biological activities of HM-PI and HS-PI were determined by measuring their antioxidant properties, antiproliferative properties against two human colon cancer cell lines, and anti-inflammatory activities in lipopolysaccharide-induced RAW 264.7 macrophages. The results showed that HS-PI has better biological activities than HM-PI, which correlated positively with the concentrations of soluble proteins, soluble polyphenols, tannins, and flavonoids. Our results showed for the first time that coproducts of hempseed processing can be potential sources of food ingredients with health-promoting properties.