Total Volatile Basic Nitrogen Analysis Research Articles

Assessing the capability of Fourier transform infrared spectroscopy in tandem with chemometric analysis for predicting poultry meat spoilage.

BackgroundUse of traditional methods for determining meat spoilage is quite laborious and time consuming. Therefore, alternative approaches are needed that can predict the spoilage of meat in a rapid, non-invasive and more elaborative way. In this regard, the spectroscopic techniques have shown their potential for predicting the microbial spoilage of meat-based products. Consequently, the present work was aimed to demonstrate the competence of Fourier transform infrared spectroscopy (FTIR) to detect spoilage in chicken fillets stored under aerobic refrigerated conditions.MethodsThis study was conducted under controlled randomized design (CRD). Chicken samples were stored for 8 days at 4 + 0.5 °C and FTIR spectra were collected at regular intervals (after every 2 days) directly from the sample surface using attenuated total reflectance during the study period. Additionally, total plate count (TPC), Entetobacteriaceae count, pH, CTn (Color transmittance number) color analysis, TVBN (total volatile basic nitrogen) contents, and shear force values were also measured through traditional approaches. FTIR spectral data were interpreted through principal component analysis (PCA) and partial least square (PLS) regression and compared with results of traditional methods for precise estimation of spoilage.ResultsResults of TPC (3.04–8.20 CFU/cm2), Entetobacteriaceae counts (2.39–6.33 CFU/cm2), pH (4.65–7.05), color (57.00–142.00 CTn), TVBN values (6.72–33.60 mg/100 g) and shear force values (8.99–39.23) were measured through traditional methods and compared with FTIR spectral data. Analysis of variance (ANOVA) was applied on data obtained through microbial and quality analyses and results revealed significant changes (P < 0.05) in the values of microbial load and quality parameters of chicken fillets during the storage. FTIR spectra were collected and PCA was applied to illuminate the wavenumbers potentially correlated to the spoilage of meat. PLS regression analysis permitted the estimates of microbial spoilage and quality parameters from the spectra with a fit of R2 = 0.66 for TPC, R2 = 0.52 for Entetobacteriaceae numbers and R2 = 0.56 for TVBN analysis of stored broiler meat.DiscussionPLS regression was applied for quantitative interpretation of spectra, which allowed estimates of microbial loads on chicken surfaces during the storage period. The results suggest that FTIR spectra retain information regarding the spoilage of poultry meat.ConclusionThe present work concluded that FTIR spectroscopy coupled with multivariate analysis can be successfully used for quantitative determination of poultry meat spoilage.

Impact of chitosan application technique on refrigerated catfish fillet quality

The aim of this study was to evaluate the effect of chitosan application method on refrigerated catfish fillet quality. Chitosan solution was prepared by dissolving a medium molecular weight chitosan (0.5%) in 1% acetic acid solution. Chitosan solution was applied to the fillets using three techniques: (1) spraying (15 mL of chitosan solution per 100 g catfish fillets), (2) dipping for 10 min at a 1:1 ratio (w/v), and (3) vacuum tumbling for 10 min at a 1:1 ratio (w/v). After application of chitosan, the fresh catfish fillets were kept under refrigerated storage (4 °C) for 16 days. The fillets were analyzed for solution pick up, pH, aerobic plate counts (APC), lipid oxidation, total volatile nitrogen (TVB-N), color, and texture. Based on aerobic plate counts and total volatile basic nitrogen analysis, catfish fillets that were vacuum tumbled with chitosan solution had an eight-day shelf life increase and sprayed or dipped fillets had four day increases compared to untreated fillets. This study suggests that vacuum tumbling with chitosan solution can deter the proliferation of aerobic bacteria in catfish fillets under refrigerated storage.

Combining Modified Atmosphere Packaging and Nisin to Preserve Atlantic Salmon

Preservation effects of modified atmosphere package combined with nisin on fresh Atlantic salmon were evaluated. Farm-raised Atlantic salmon were purchased from the local market and packaged using either 19 % CO2: 70 % N2 : 11 % O2 , 38 % CO2 : 51 % N2 : 11 % O2, and under atmospheric air (with and without nisin at 400 IU/g) resulting in a total of 6 treatments. The microbiological (aerobic plate count, psychrotrophic bacteria, and lactic acid bacteria) and the total volatile basic nitrogen analyses were evaluated on Day 0, 2, 4, 7 and 10. Package headspace and sensory evaluation were also conducted on Day 0, 2 and 4. The presence of CO2 effectively inhibited the growth of all three types of bacteria while nisin significantly inhibited the growth of aerobic microorganisms with less impact on lactic acid bacteria. The TVB-N test indicated that CO2 delayed the spoilage of Atlantic salmon while nisin had a lesser but measurable impact on Atlantic salmon shelf-life. The experiments support the potential for combining modified atmosphere package and nisin as an effective method to limit the spoilage of Atlantic salmon compare to traditional preservation methods.

Correlation between biochemical and sensory quality indices in hake stored in ice

Whole gutted hake was stored for 25 days in ice. Changes in pH, trimethylamine nitrogen (TMA-N), total volatile basic nitrogen (TVB-N), and lipid deterioration [2-thiobarbituric acid (TBA) index] was studied, and correlated with sensory analysis (inspection and tasting). There was a very high correlation between TMA-N and TVB-N indices. TBA levels remained very low throughout the assay and were correlated with the results found in the tasting analysis, where the tasters did not detect any rancidity. However, the TBA results had a very low correlation with the inspection analysis and the TMA-N and TVB-N analyses. The pH, TMA-N and TVB-N indices had a very high correlation with the sensory analyses, which means these parameters are more suitable as indices for spoilage of hake.