Siroj Pokharel

Dr. Siroj Pokharel


Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2013 in Journal of Animal Science
Verified
Journal Article
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JHJ. E. Hergenreder
J. E. Hergenreder
JHJ. J. Hosch
J. J. Hosch
KVK. A. Varnold
K. A. Varnold
AHA. L. Haack
A. L. Haack
LSL. S. Senaratne
L. S. Senaratne
CCC. R. Calkins
C. R. Calkins
The objective of this study was to evaluate processing methods for frozen beef subprimals; the effects of freezing and thawing rates on tenderness, sensory properties, and retail display were evaluated. There were 6 treatments: fresh, never frozen 14 d wet aged (14D); fresh, never frozen 21 d wet aged (21D); blast frozen–fast thawed (BF); blast frozen–slow thawed (BS); conventionally frozen–fast thawed (CF); and conventionally frozen–slow thawed (CS). All frozen beef subprimals were aged for 14 d before freezing. Three beef subprimal cuts, rib eye roll (n = 90), strip loin (n = 90), and top sirloin butt (n = 90), were used with 3 replications of 5 samples per treatment per week (total of 9 wk, n = 270). Blast freezing occurred by placing spacers between the boxes of meat on pallets at −28°C with high air velocity for 3 to 5 d. Conventional freezing occurred with boxes of meat stacked on pallets and placed in a −28°C freezer with minimal air movement for at least 10 d. Fast thawing of subprimals (to an internal temperature of −1°C to 1°C) occurred by immersion in a circulating water bath ( 0.05). All LL and LT beef steaks had approximately 4 d to 40% discoloration, and all GM steaks had over 3 d to 40% discoloration. Steaks from the LL and LT began to discolor at about 3 d, and the GM began to discolor after 1 d. For all beef subprimals, purge loss during storage and thawing was significantly greater for the slow-thawed subprimals (P < 0.01), and all fast-thawed subprimals were equal or superior to 14D and 21D (P < 0.01) in storage and thawing purge. During retail display, the greatest purge loss occurred in fast-thawed treatments (P < 0.01). Overall, freezing rate did not affect purge loss, and neither freezing nor thawing rates had significant meaningful effects on WBS, and sensory properties were comparable with fresh, never-frozen subprimals. Copyright © 2013. American Society of Animal Science .

4 November 2022 in Meat Science
Verified
Journal Article
Open access
SLSherita Li
Sherita Li
HKHaley M. Konoval
Haley M. Konoval
SMSamantha Marecek
Samantha Marecek
ALAmanda A. Lathrop
Amanda A. Lathrop
SFSofia Feng
Sofia Feng
SPSiroj Pokharel
Siroj Pokharel
Escherichia coli (E. coli) O157:H7- contaminated pork and production environments, are often a major source of foodborne outbreaks. This study evaluated the inhibition of E. coli O157:H7 on artificially contaminated raw pork loins using lytic bacteriophage (phage) and lactic acid (LA). Pork samples were inoculated with 106 CFU/mL of E. coli O157:H7 cocktail and stored at 4 °C for 30 min for the initial surface attachment. Inoculated pork loins were randomly assigned to a treatment group (Control, DI water, LA 2.5%, phage 5%, and LA 2.5% + phage 5%; n = 6/group/replication). Following antimicrobial treatments and marination for 1 h, surface microbial population was enumerated. Phage 5% significantly reduced (P < 0.05) the microbial load by 1.90 logs in pre-tenderized loins and > 2.50 logs in post-tenderized loins. Likewise, the combined treatment of phage 5% and LA 2.5% significantly reduced (P < 0.05) the microbial load by 1.89 logs in pre-tenderized loins and > 1.75 logs in post-tenderized loins. The data showed that the use of lytic bacteriophages and lactic acid as antimicrobials can result in a reduced risk of E. coli O157:H7 on the surface of pork loins.

1 December 2021 in Food Microbiology
Verified
Journal Article
Open access
NWNicole Walker
Nicole Walker
SLSherita Li
Sherita Li
HSHannah Strauss
Hannah Strauss
SPSiroj Pokharel
Siroj Pokharel
Bacterial food poisoning cases due to Salmonella have been linked with a variety of poultry products. This study evaluated the effects of a Salmonella-specific Lytic bacteriophage and Lactobionic acid (LBA) on Salmonella Typhimurium DT 104 growth on raw chicken breast meat. Each chicken breast was randomly assigned to a treatment group (Control, DI water, phage 1%, phage 5%, LBA 10 mg/mL, LBA 20 mg/mL, and phage 5% + LBA 20 mg/mL) with four chicken breasts per group. Samples were inoculated with 106 CFU/mL of Salmonella and stored at 4 °C for 30 min. The inoculated chicken breasts were randomly assigned to different storage time (0 h, 1 h, 24 h, or 48 h). Both time and treatment showed significance reduction (P < 0.0001) of microbial growth. The weight loss was significantly different (P < 0.0001) between treatments. The LBA treatments were not effective when compared to the control group, but Lytic bacteriophage significantly reduced the amount of microbial growth.

1 September 2010 in Journal of Animal Science
Verified
Journal Article
Closed access
PDF file
LSL. S. Senaratne
L. S. Senaratne
CCC. R. Calkins
C. R. Calkins
AMA. S. de Mello
A. S. de Mello
SPSiroj Pokharel
Siroj Pokharel
JHJ. B. Hinkle
J. B. Hinkle
Intramuscular tenderness variation and muscle fiber orientation of beef M. adductor femoris (AF), M. biceps femoris (BF), M. gracilis (GL), M. pectineus (PT), M. sartorius (SR), M. semimembranosus (SM), M. semitendinosus (SO), M. vastus intermedius (VI), M. vastus medialis (VM), and M. vastus lateralis (VL) were investigated. The USDA Choice boxed beef subprimals were purchased and aged for 14 d from boxed date. The AF, BF, GL, PT, SR, SM, SO, VI, VM, and VL (n = 10 each) were fabricated from subprimals. Crust-frozen AF, BF, SO, SM, and VL were cut into 2.54-cm steaks perpendicular to the long axis and grilled (71°C). The PT, SR, VI, and VM were grilled (71°C) as whole muscles, whereas the GL was grilled after cutting into anterior and posterior regions. Grilled muscles were cut into equal size sections perpendicular to long axis of muscles. Location-specific cores were prepared from each steak/section, and Warner-Bratzler shear force (WBSF) was measured. The muscle fiber orientations of BF, PT, and VI were bipennate, SR and SO were fusiform, and AD, SM, VL, GL, and VM were unipennate. The overall mean WBSF values for BF, SO, AF, SM, PT, SR, GL, VI, VM, and VL were 5.62, 4.86, 4.18, 4.90, 3.76, 4.44, 4.75, 4.78, 4.24, and 6.53 kg, respectively. Based on WBSF values, PT was tender, BF and VL were tough, and VM, VI, SM, GL SR, AF, and SO were intermediate. The first 2 proximal steaks of long head BF were more tender than the rest (P < 0.05). In the SO, the tenderness decreased from the middle of the muscle to both ends (P < 0.05). The anterior sides of the long head BF and SO were tougher than their posterior sides (P < 0.05).The first 4 steaks of the SM were more tender than the rest of the muscle (P < 0.05). There was a significant tenderness increment from the middle of the AF and SR to both ends of each muscle (P < 0.05). The medial side of the VI was more tender than its lateral side (P < 0.05). The VM had its smallest shear force value at the most distal end compared with the rest (P < 0.05). Dry or moist heat oven roasting, as compared with grilling, significantly tenderized SO (P = 0.002) and VL (P < 0.0001) muscles. There were no significant WBSF value differences along the PT and between anterior and posterior regions of the GL. Based on WBSF ratings, PT, SR, VM, GL, and VI could be merchandized as single muscle steaks or medallions and the first 2 to 4 steaks of long head BF, SM, and AF could be marketed as premium-quality steaks. This detailed information on intramuscular tenderness and muscle fiber orientation variations of the round muscles could be used in a value added strategy for the beef round. Copyright © 2010. American Society of Animal Science .

1 April 2011 in Journal of Animal Science
Verified
Journal Article
Closed access
PDF file
KJK. H. Jenkins
K. H. Jenkins
JVJ. T. Vasconcelos
J. T. Vasconcelos
JHJ. B. Hinkle
J. B. Hinkle
SFS. A. Furman
S. A. Furman
AMA. S. de Mello
A. S. de Mello
CCC. R. Calkins
C. R. Calkins
Whole field peas were fed at 0, 10, 20, and 30% of DM to 139 yearling steers (British cross; 409 ± 31 kg of initial BW) for a 119-d finishing period. Carcass data and Choice grade strip loins (n = 98) were collected from a commercial abattoir in Lexington, Nebraska. Consumer sensory and Warner-Bratzler shear force analyses were performed on 2.5-cm strip steaks. No differences (P ≥ 0.17) were observed in final BW, ADG, DMI, and G:F of steers. Likewise, no differences (P ≥ 0.23) were observed for HCW, LM area, fat thickness at the 12th rib, yield grade, and marbling scores. However, KPH responded quadratically to increasing dietary amount of field peas (P = 0.02). Regarding the sensorial analysis, feeding peas linearly increased subjective tenderness (P < 0.01) and led to a quadratic response of overall like ratings (P = 0.01) and flavor like ratings (P = 0.12). Feeding peas did not alter (P ≥ 0.64) juiciness, but decreased shear force values linearly when quantities were increased (P = 0.02). These data suggest that feeding peas does not affect steer performance or carcass characteristics differently from dry-rolled corn, but does improve objective and subjective tenderness, overall desirability, and flavor of beef. Field peas could be fed to cattle and give positive attributes to the quality of the meat up to 30% inclusion in the diet. Copyright © 2011. American Society of Animal Science .

29 August 2020 in Journal of Food Science Education
Verified
Journal Article
Open access
PDF file
DODuygu Ercan Oruc
Duygu Ercan Oruc
SPSiroj Pokharel
Siroj Pokharel
RARamaswamy C. Anantheswaran
Ramaswamy C. Anantheswaran
MBMartin W. Bucknavage
Martin W. Bucknavage
HGHassan Gourama
Hassan Gourama
CCCatherine N. Cutter
Catherine N. Cutter
Understanding and enacting standardized food safety practices in a global economy is important. In 2018, a comprehensive food safety training program, including courses in sanitation, food microbiology and mycology, thermal processing, Hazard Analysis and Critical Control Points, cereal quality, and food defense, was delivered to food industry professionals, students, and faculty members in Kyiv, Ukraine. The curriculum included lectures, hands‐on laboratories, as well as case studies and product development activities. Prior to the delivery of the curriculum, demographic data were collected ( n = 33). Participants’ food safety knowledge, attitude, behavior, and skills were assessed prior to the program starting and after program completion (immediately and 6 months later). Food safety knowledge of participants immediately after the program and 6 months later was significantly higher ( p < .05) than before the program started. Immediately after the delivery of the curriculum and 6 months later, the participants’ food safety attitude and behavior were positively enhanced, with long‐term, sustained changes in proper food safety practices, training requirements, and regulations. Additionally, handwashing skills were improved significantly because of the training program. Use of case studies and product development activities demonstrated positive impacts on participants’ food safety learning experience in terms of awareness of their knowledge, communication skills, and the ability to connect scientific concepts and real‐life examples. To our knowledge, little information exists on the use of these training tools with international audiences. This information may be useful to food industry professionals, researchers, and academics who are interested in finding ways to improve the global safety of the food supply through training and education.