Evaluation of peroxyacetic acid, liquid buffered vinegar, and cultured dextrose fermentate as potential antimicrobial interventions for raw chicken livers

This study aimed to evaluate the use of peroxyacetic acid (PAA), buffered vinegar (BV), and cultured dextrose fermentate (CDF) to reduce Salmonella on artificially inoculated raw chicken livers, one of the most consumed offal around the world. Samples were inoculated with a 5-strain cocktail of poultry-borne Salmonella to obtain 106 CFU/g and immersed for 90 s with agitation in one of the following treatments: distilled water (control), 450 ppm PAA, 2.0% (w/v) BV, or 1.5% (w/v) CDF, prior to storing at 4oC. Salmonella was enumerated on XLD agar and monitored for 14 days. Data were analyzed using analysis of covariance. After immersion, there was a significant Salmonella reduction (p \u3c .05) with all treatments, including the control. PAA resulted in the greatest numerical reduction at 0.65 ± 0.12 log; however, there were no significant differences in the reductions among all other treatments (p \u3e .05). After 14 days, higher numerical reductions were observed for PAA, but only when compared to CDF. Although similar reductions (p \u3e .05) were noted after 14 days except for CDF, Salmonella counts were lowest in all timepoints when PAA was used. PAA and CDF inhibited the growth of aerobic bacteria until day 3 while BV inhibited the growth up to 7 days. Regarding objective color, chicken livers immersed in PAA became lighter, but the difference was not sustained over time. No differences were observed in redness or yellowness values across any treatments

Performance of two handheld NIR spectrometers to quantify crude protein of composite animal forage and feedstuff

Two handheld near infrared (NIR) spectrometers were used to quantify crude protein (CP) content of mixed forage and feedstuff composed of Sweet Bran, distiller’s grains, corn silage, and corn stalk. First was a transportable spectrometer, which measured in the visible and NIR ranges (320–2500 nm) with a spectral interval of 1 nm (H1). Second was a smartphone spectrometer, which measured from 900–1700 nm with a spectral interval of 4 nm (H2). Spectral data of 147 forage and feed samples were collected by both handheld instruments and split into calibration (n= 120) and validation (n= 27) sets. For H1, only absorbances in the NIR region (780–2500 nm) were used in the multivariate analyses, while for H2, absorbances in the second and third overtone regions (940–1660 nm) were used. Principal component analysis (PCA) and partial least squares (PLS) regression models were developed using mean-centered data that had been preprocessed using standard normal variate (SNV) or Savitzky-Golay first derivative (SG1) or second derivative (SG2) algorithm. PCA models showed two major groups—one with Sweet Bran and distillers grains, and the other with corn silage and corn stalk. Using H1 spectra, the PLS regression model that best predicted CP followed SG1 preprocessing. This model had low root mean square error of prediction (RMSEP= 2.22%) and high ratio of prediction to deviation (RPD= 5.24). With H2 spectra, the model best predicting CP was based on SG2 preprocessing, returning RMSEP= 2.05% and RPD= 5.74. These values were not practically different than those of H1, indicating similar performance of the two devices despite having absorbance measurements only in the second and third overtone regions with H2. The result of this study showed that both handheld NIR instruments can accurately measure forage and feed CP during screening, quality, and process control applications

Effects of high-pressure processing on cooked color and eating qualities of dark-cutting beef

High meat pH leads to an undercooked or an abnormal pink appearance in fully-cooked product. High-pressure processing (HPP) promotes protein denaturation. The objective was to evaluate the effects of HPP on cooked steak color and sensory attributes of dark-cutting beef. USDA Choice (mean pH = 5.5) and dark-cutting (mean pH = 6.3) strip loin sections were vacuum packaged and treated with 0 (no HPP), 300, 450, and 600 MPa of pressure for 90 s using chilled water. Steaks were randomly assigned to measure external cooked color, Warner- Bratzler shear force, and trained sensory panel. Applying 300 MPa of pressure improved ( P \u3c 0.05) redness of raw dark-cutting steaks compared with control. HPP treatments did not influence ( P \u3e 0.05) a∗ and chroma of the external cooked steak color. HPP treatments also did not affect ( P \u3e 0.05) initial juiciness, sustained juiciness, beef flavor intensity, or overall acceptability. However, 600 MPa made dark-cutting steaks tougher and lighter ( P \u3c 0.05) in appearance than all other treatments. In conclusion, low (300 MPa) and moderate (450 MPa) pressure levels improved raw steak redness without affecting the eating qualities of dark-cutting cooked steaks. HPP did not minimize the undercooked appearance commonly associated with high-pH beef

Comparison of Hermetic Storage of Wheat with Traditional Storage Methods in India

India is among the countries experiencing high postharvest losses. Four hermetic bags, two metallic bins, and two gunny bag (also known as jute or burlap bag) piles each containing 1 tonne of wheat were instrumented with temperature, relative humidity, and carbon dioxide sensors. Representative samples from each structure were collected each month and tests for moisture, germination, insect-damaged grain, and milling yield were performed. After nine months, wheat stored in hermetic bags had higher germination (87%) and lower insect-damaged grain percentages (0% to 0.33% with a mean value of 0.2%). Hermetic bags with deliberately introduced Rhyzopertha dominica successfully eliminated the pests. Gunny bag piles had infestations; metallic bins also were infested. Wheat moisture content in all structures varied depending upon ambient conditions; moisture variation was largest in gunny bag piles. Milling yields were lowest for gunny bag piles. Hermetic bags can be an effective and environmentally friendly solution for reducing storage losses of wheat in India

Effect of scanning samples through polypropylene film on predicting nitrogen content of forage using handheld NIR

This study examined the effect of collecting near infrared (NIR) spectra of forage samples through a transparent polypropylene (PP) plastic film instead of glass cups on calibrating two handheld NIR spectrometers to nitrogen content (N). The first device was a transportable spectrometer (H1) covering 790–2500 nm at 1 nm interval, while the second device was a smartphone spectrometer (H2) covering 900–1700 nm at 4 nm interval. The spectra from each spectrometer were subjected to principal component analysis (PCA) to identify wavebands for PP packaging that would interfere in subsequent partial least squares (PLS) regression modeling to predict N. PCA results showed that the loadings of the first principal component (PC1) of the first derivative of the spectra from H1 and loadings of the second principal component (PC2) of the second derivative of the spectra from H2 were useful in identifying wavebands due to PP film. Regression models for H1 had better prediction performance when spectra were collected through glass than through PP films, in terms of coefficient of determination (r2 = 0.958), standard error of prediction (SEP = 0.96 g kg−1), and ratio of performance to deviation (RPD) = 4.93 vs. (r2 = 0.942, −1 SEP = 1.13 g kg , and RPD = 4.17). Similar results were obtained for H2 using spectra collected 2 −1 2 through glass (r = 0.821, SEP = 1.73 g kg , and RPD = 2.72) than through PP (r = 0.499, SEP = −1 2.99 g kg , and RPD = 1.57). Removing peaks due to PP in the sample spectra improved the PLS 2 −1 2 modelsforH1(r =0.959,SEP=0.94gkg ,andRPD=5.02),butnotforH2(r =0.521,SEP= −1 3.17gkg ,andRPD=1.49).Hence, scanning samples through PP film scan reduce the accuracy of predicting N, but for some handheld NIR spectrometers, this could be overcome by excluding wavebands due to PP

Comparison of Hermetic Storage of Wheat with Traditional Storage Methods in India

India is among the countries experiencing high postharvest losses. Four hermetic bags, two metallic bins, and two gunny bag (also known as jute or burlap bag) piles each containing 1 tonne of wheat were instrumented with temperature, relative humidity, and carbon dioxide sensors. Representative samples from each structure were collected each month and tests for moisture, germination, insect-damaged grain, and milling yield were performed. After nine months, wheat stored in hermetic bags had higher germination (87%) and lower insect-damaged grain percentages (0% to 0.33% with a mean value of 0.2%). Hermetic bags with deliberately introduced Rhyzopertha dominica successfully eliminated the pests. Gunny bag piles had infestations; metallic bins also were infested. Wheat moisture content in all structures varied depending upon ambient conditions; moisture variation was largest in gunny bag piles. Milling yields were lowest for gunny bag piles. Hermetic bags can be an effective and environmentally friendly solution for reducing storage losses of wheat in India

Use of High-Pressure Processing to Improve the Redness of Dark-Cutting Beef

The objective was to evaluate the effects of high-pressure processing (HPP) levels on retail color of dark-cutting beef. Eight USDA Choice (mean pH = 5.5; normal-pH beef) and 12 dark-cutting (mean pH = 6.3) strip loins were obtained from a commercial packing plant within 2 d of harvest. Dark-cutting loins were cut into equal sections, vacuum packaged, and randomly assigned to 0 (no HPP), 300, 450, and 600 MPa of pressure for 90 s using chilled water. Following 48 h of dark storage at 2°C, dark-cutting loin sections were cut into 1.9-cm-thick steaks, placed in Styrofoam trays overwrapped in polyvinyl chloride (PVC) film, and placed in a simulated retail display for 8 d. The surface color readings were measured every 24 h using a HunterLab MiniScan XE Plus spectrophotometer, whereas a trained color panel (n = 6) evaluated discoloration, paleness, and lean color on steaks. Lipid oxidation was evaluated on day 0, 4, and 8 of retail display, and structural changes were determined using light microscopy on day 0 of display. There was a significant HPP level × day of retail display interaction for all instrumental color measurements. Throughout the retail display, L* values of 450 and 600 MPa applied steaks were greater (P \u3c 0.05) than 300 MPa and controls. There was a significant pressure level × day of retail display interaction when panelists evaluated lean color and discoloration. Steaks treated at 300 MPa exhibited brighter red color and lower (P = 0.0023) thiobarbituric acid reactive substance values than other pressure levels and normal-pH control steaks. Light microscopy analysis indicated that HPP increased space between muscle structures. In conclusion, low (300 MPa) and moderate (450 MPa) pressure levels can improve redness of dark-cutting steaks