Showing 4 results for Ezzatpanah
Volume 15, Issue 6 (11-2013)
Abstract
The present study was carried out to investigate the effect of various refining processes’ conditions on conjugated dienes in soybean oil. Conjugated dienes contents of soybean oil were found to undergo reduction in neutralization and bleaching steps while being increased in deodorization. It was observed that alkali refining (neutralization) through 12 and 14 °Bé, bleaching with either acid activated clay or a mixture of acid activated clay plus activated carbon at 110˚C along with deodorization at 220˚C and at 4 or 8 mbar had the highest effect on reduction of conjugated dienes in soybean oil. Conjugated dienes were in good correlation with peroxide value, free fatty acids, Totox value and as well with p-anisidine value in each step. Overall, alkali refining proved to be the most effective step in reduction of conjugated dienes, free fatty acids and oxidative stability index. Peroxide value, p-anisidine and Totox values changed during refining and got significantly decreased in deodorization.
Volume 16, Issue 7 (Supplementary Issue - 2014)
Abstract
The presence of antibacterial activity in bovine β-lactoglobulin and in α-lactalbumin hydrolysates was investigated. The Plasmin-Digest of β-lactoglobulin (PDβ) and of α-lactalbumin (PDα) were fractionated, using reversed phase high performance liquid chromatography. The antibacterial activity of β-lactoglobulin, α-lactalbumin, nisin, plasmin, PDβ and PDα were in vitro tested against pathogenic (Escherichia coli and Staphylococcus aureus) and probiotic (Lactobacillus casei and Lactobacillus acidophilus) bacteria. Although α-lactalbumin, β-lactoglobulin and plasmin exhibited no antibacterial activity, PDβ, PDα and nisin revealed antibacterial activity against the bacteria tested. The Minimum Inhibitory Concentration (MIC) of these compounds was determined for the bacteria cultures. Similar to nisin, the MIC of PDβ and of PDα against Gram-positive bacteria was recorded as considerably lower than the MICs against Gram-negative bacteria. The study also evaluated the effect of PDβ, PDα and nisin on the growth curves and on the plate count confirmations of the target bacteria. The results revealed that nisin, PDβ and PDα have inhibitory effects on the lag phase, maximum OD620 and on plate count confirmation of the bacteria tested. The maximum inhibitory effect of these compounds was created during the log phase. Their inhibitory effects depended upon their concentrations, higher concentration causing stronger antibacterial activity. The PDβ and PDα proved more active against Gram-negative bacteria than did nisin, but nisin revealed substantial inhibitory activity against Gram-positive bacteria.
Farnoush Lavafpour, Farzaneh Shojaei Azad, Hengameh Sadeghi, Somayeh Siahvoshi, Hamid Ezzatpanah,
Volume 17, Issue 102 (August 2020)
Abstract
Food safety is a crucial goal for dairy industry. Cleaning of dairy equipment is critical not only to meet milk and milk product`s standards but also from environmental points of view. Sanitation challenges of heat exchangers and membranes dominates over the other deficiencies considerably in dairy processing steps that have been hardly affected by conventional methods(conventionally)that are updated through this paper by utilizingemerging paths such as enzymes and ultrasound, respectively. Moreover, incoming materials specifications, importantly composition (i.e. organic or inorganic), concentration, and temperatureare known as prominent impactful parameters on either milk components deposition on heated surfaces or imposing fouling on membranes. Although, cleaning agents` properties namely: concentration, flow, pH, sheer stress, and temperature are influential features, sanitizers selection and their application sequence in cleaning program should be considered as the most determinants factors. The article goes onadvancement of control and monitoringmethods of sanitation programs from COD, Calcium, and turbidity to conductivity and ultrasound sensors. Finally, it discusses a brief solution to tackle some environmental problems regarding the usage of chemicals for cleaning in dairy industry.
Farnoush Lavaf Pour, Farzaneh Shojaei Azad, Hengameh Sadeghi, Somayeh Siahvoshi, Hamid Ezzatpanah,
Volume 18, Issue 115 (September 2021)
Abstract
A common practice and crucial step to control mastitis and maintain the high-quality of raw milk is teat disinfection which divides into pre-, immediately prior to, and post-milking. Accordingly, dipping and spraying procedures have been applied to prevent environmental and contagious mastitis as well as reduction of microbial load of raw milk. Quantitative tests such as somatic cell counts in raw milk are commonly used to monitor dramatic change of normal to sub-clinical (250000≤ cell mL-1), and clinical infected udder. It is assumed that pre-milking disinfection is a suitable strategy to tackle sub-clinical environmental mastitis whereas post-milking method is recommended to manage contiguous one. Pre-dipping effectively declines bacterial count in raw milk. Although, post-milking disinfection significantly reduces microbial contamination from liner and cleaning step, it is not effective on bacterial load from hands of milker, rinse water and used paper towel. The usage of disinfectants in major milk producer countries varies extensively, for instance more than two third of teat disinfectants in New Zealand is iodophor, followed by 15% chlorhexidine and 15% dodecylbenzene sulphonate. Iodophor has been used as pre- and post- sanitizer in concentration of 0.3% but it is allowable from 0.1-0.25% in UK. According to the regulations of the USA, Spain, and Canada, chlorhexidine can be used in the range of 0.11-0.5%, meanwhile Danish and Americans’ law regulated the usage of dodecylbenzene sulphonate in the vicinity of 2%. Hypochlorite has been taken into account as pre- and post- sanitizer from 0.1 to 4 % but regulated up to 0.2 in UK and 0.3% in US and CA. Likewise chlorhexidine, dodecylbenzene sulphonate, and quaternary ammonium compounds are used as post-milking. Bacteriocin is a teat disinfectant in France whereas slightly acidic electrolyzed water has been introduced as emerging pre- and post- sanitizer.
