Optical Refractometer Research Articles

Investigation of the effect of specific gravity and pH on the fermentation period of a single and combined algae species as a potential bioethanol feedstock

Algae has garnered significant attention as a promising biomass source for bioethanol production and as a solution to sustainability issues. Nevertheless, the disruption of complex carbohydrates required for yeast fermentation occurs during algae cultivation. The fermentation process, which is critical for producing bioethanol as a cost-effective and environmentally friendly alternative fuel, may be improved by meticulously managing the parameters that influence fermentation, such as specific gravity and pH. Bioethanol was produced from algae species (Navicula sp., Oscillatoria sp. and diatoms) using simultaneous saccharification and fermentation (SSF) processes. A control, single and combined algal species were prepared in the following formation: Oscillatoria sp. and Navicula sp. (sample A), Oscillatoria sp. (sample B), diatom and Oscillatoria sp. (sample C), Navicula sp. (sample D), and diatoms, Navicula sp. and Oscillatoria sp (sample E). The daily bioethanol concentrations in the fermentation medium were measured using a digital optical refractometer, and a Two-way ANOVA analysis (p < 0.05) was conducted to determine the differences between the period of fermentation and the bioethanol concentration. Additionally, the pH and specific gravity were assessed. The Two-way ANOVA analysis conducted indicated that the F-values surpassed the F-critical values and the p-values were all notably below 0.05, suggesting a statistically significant distinction between the samples in their fermentation periods and bioethanol concentration. The highest concentration was observed in sample E at 39.53 g/L, followed by samples C and D at 37.36 g/L, samples A and B at 35.10 g/L, and the control at 4.78 g/L. The findings showed that mixed cultures could potentially improve ethanol yield. The optimal fermentation period was determined to be 72 h. The pH levels in the control and algae samples varied between 6.5 and 6.7 and 7.06 to 8.42, respectively. The specific gravity in the control and algae samples ranged from 1.003 to 1.004 and 1.023 to 1.037, respectively. During algae fermentation, specific gravity initially increased, then stabilized before decreasing. pH levels correlated with fermentation duration. Understanding these factors is crucial for maximizing bioethanol production. This discovery could lead to exploring how different algae species interact to improve cultivation methods.

D-shaped optical fiber-based refractometer for olive oil adulteration detection

Extra virgin olive oil is a product in great demand, due to its popularity as the healthiest cooking oil. Thanks to its popularity and high price, extra virgin olive oil is also a common target of adulterators who add other vegetable oils in order to increase the volume of the final product. This practice is specially harmful to consumers who choose olive oil due to dietary restrictions, in addition to directly affecting producers, due to unfair competition. Based on this scenario, this work presents a D-shaped optical fiber-based refractive index sensor to detect adulteration of olive oil caused by the addition of canola, corn, cotton, soybean and sunflower oils. The device fabrication and characterization processes are presented, detailing the instrumentation used and the methodology adopted during the measurements. The sensor sensitivity, measured against the added percentage of contaminants, was determined as 0.037 dB/%. The results show that the sensor is capable of detecting adulterations from additions of any combination of the five adulterants greater than 9% of the total volume.

Salivary IgG and IgA in newborn calves and the possible role in the assessment of passive immunity transfer.

The transfer of immunoglobulins from the mother to newborns is widely recognized as a critical event for safeguarding offspring against potentially life-threatening infectious diseases. Mainly for this reason, this study aimed to assess the concentrations of immunoglobulin G (IgG) and immunoglobulin A (IgA) in the saliva of newborn calves and explore its potential use for monitoring passive immunity transfer from cows to calves, as also to evaluate how colostrum intake affects serum and saliva IgG and IgA concentrations. The quality of colostrum samples was evaluated using an optical refractometer before administration to the calves. Saliva and blood samples from 24 calves were obtained at the day of birth (T0) and 2 days after (T2) for determination of serum concentrations of total protein by refractometer, IgG and IgA (both on serum and saliva) by ELISA test. Positive correlations were observed between salivary IgA at T2 and salivary IgG at T2. A significant increase in both IgG and IgA levels in calf serum and saliva was noted. Salivary IgA levels can reflect salivary IgG levels. These findings suggest the potential utility of IgA in monitoring passive immunity transfer, and do not exclude saliva as an alternative, practical, and non-invasive matrix for assessing passive immunity transfer.

Application of fiber loop ringdown spectroscopy technique for a new approach to beta-amyloid monitoring for Alzheimer Disease’s early detection

A novel fiber optic biosensor was purposed for a new approach to monitor amyloid beta protein fragment 1–42 (Aβ42) for Alzheimer’s Disease (AD) early detection. The sensor was fabricated by etching a part of fiber from single mode fiber loop in pure hydrofluoric acid solution and utilized as a Local Optical Refractometer (LOR) to monitor the change Aβ42 concentration in Artificial Cerebrospinal Fluid (ACSF). The Fiber Loop Ringdown Spectroscopy (FLRDS) technique is an ultra-sensitive measurement technique with low-cost, high sensitivity, real-time measurement, continuous measurement and portability features that was utilized with a fiber optic sensor for the first time for the detection of a biological signature in an ACSF environment. Here, the measurement is based on the total optical loss detection when specially fabricated sensor heads were immersed into ACSF solutions with and without different concentrations of Aβ42 biomarkers since the bulk refractive index change was performed. Baseline stability and the reference ring down times of the sensor head were measured in the air as 0.87% and 441.6 μs ± 3.9 μs, respectively. Afterward, the total optical loss of the system was measured when the sensor head was immersed in deionized water, ACSF solution, and ACSF solutions with Aβ42 in different concentrations. The lowest Aβ42 concentration of 2 ppm was detected by LOR. Results showed that LOR fabricated by single-mode fibers for FLRDS system design are promising candidates to be utilized as fiber optic biosensors after sensor head modification and have a high potential for early detection applications of not only AD but possibly also several fatal diseases such as diabetes and cancer.

Comparison of Salinity Measurement Based on Optical Refractometer and Electric Conductivity: A Case Study of Urea in Seawater

Comparison of Salinity Measurement Based on Optical Refractometer and Electric Conductivity: A Case Study of Urea in Seawater

Contribution of dissolved organic matter to seawater salinity measured by optic refractometer: a case study of DOM extracted from Aoshan Bay

Dissolved organic matter (DOM) in seawater, consisted of a complex mixture of compounds and accounted for about 90% of marine organic carbon, is an important part of the global carbon cycle and also a part of absolute salinity of seawater. As the components of DOM are non-ionized in seawater, electric conductivity measurement cannot observe its contribution to salinity, which could lead to measurement error in salinity. Salinity measurement based on optic refractive index could reveal contribution of all dissolved matters in seawater including both non-ionized and ionized components. In this paper, a comparative study of DOM contribution to the salinity measurement by optic refractive index method and electric conductivity method was carried out for the first time. Adding DOM, extracted from Aoshan Bay, Qingdao, China, into Chinese Standard Seawater, our experimental results showed an increase of optic refractive index at 1.19×10-4 ± 4×10-6 per 1g/kg of DOM, which corresponds to a practical salinity increase of 0.697 ± 0.036 PSU per 1 g/kg of DOM. While, the conductivity of seawater measured by a conductivity-temperature sensor showed a decrease of 0.00065 ± 0.00008 mS/cm per 1 g/kg of DOM, which corresponded to a decrease of salinity at 0.00052 ± 0.00007 PSU per 1 g/kg of DOM. By comparing the optic and electric measurement results, the contribution of non-conductive components in the dissolved organic matters to salinity could be distinguished, which has great significance for the measurement of absolute salinity, global carbon cycle etc.

Use of a Visual Scoring System to Assess External Udder Conformation and Its Relationship to Colostrum Quality and Lamb Growth Rates.

In sheep raised for meat production, the relationship between external udder conformation, colostrum quality, and lamb growth rates has not received much attention. We hypothesized that ewes with a more desirable udder conformation at lambing would have greater colostrum quality and greater growth rates in lambs. Fifty Suffolk ewes were used in this study. Within 6-8 h of parturition, colostrum samples from both halves of the udder were collected and visual scoring of the udder was conducted. Colostrum quality was measured for total proteins using both optical and Brix refractometers. On day 2, day 45, and day 60 after parturition, lamb weights were recorded, and udder conformation measurements were repeated. A visual scoring system evaluating udder floor (scale 1-4), udder depth (scale 1-9), teat placement (scale 1-9), teat/mammary lesions (present or absent), and the presence of wool (present or absent) was used to assess the external udder conformation. Normal udder parameters included udder depth scores of 5 or 6; udder floor scores of 1 or 2; teat placement scores of 4, 5, or 6; and the absence of teat/mammary lesions and wool. All ewes not meeting normal parameters were considered to have an abnormal udder. The data were analyzed using the GLM procedure. Mean total colostrum protein was greater (p = 0.03) in ewes displaying a 'normal' udder conformation compared with those with an 'abnormal' conformation (14.82 ± 0.5 and 13.31 ± 0.3 mg/dL, respectively). Mean Brix values were also greater (p = 0.03) for ewes with a 'normal' udder compared to an abnormal udder confirmation (21.70 ± 0.8 and 19.54 ± 0.5, respectively). On day 2 after parturition, the mean lamb body weight was not different between ewes with 'normal' and abnormal udders (5.38 ± 0.26 vs. 5.46 ± 0.15). No differences (p > 0.05) in lamb weights were detected between ewes with normal and abnormal udder conformations on day 45 and 60 after parturition. These data provide evidence of greater colostrum total protein values and greater Brix values present in ewes with a 'normal' udder conformation. There were no differences in the weights of lambs born to ewes with normal or abnormal udder conformations.

Estimating IgG concentration directly by radial immunodiffusion or indirectly by refractometry measure of serum total protein lack precision.

To establish and compare the precision of serum total protein (STP) measured by an optical refractometer to the precision of IgG concentrations measured using radial immunodiffusion (RID), the reference test for quantifying IgG in neonatal calves. 6 sera with previously measured IgG concentration using RID from neonatal beef calves were selected from 3 stratum: low-serum IgG stratum between >5.0 and <15.0g/L(n = 4); moderate-serum IgG stratum between 35.0-45.0g/L(n = 1); high-serum IgG stratum between 60.0-70.0g/L(n = 1). STP was measured 13 times with an optical refractometer. IgG concentrations were measured 28 times with a commercial bovine IgG RID for each sera. The homogeneity of variance within the tests was evaluated with the Levene test (α = 0.10). Unrestricted random sampling bootstrapping (5,000 repetitions) was used to calculate the coefficient of variation (CV) for each serum and test. The homogeneity of variance between simulated test CVs by serum was evaluated (α = 0.10). Differences between simulated test CV by serum were assessed with the Kruskal-Wallis test (α = 0.05). No difference was observed in the variance for STP between sera (P = .39). The average CV for STP was 4.2%, 10.1% for the low IgG stratum, and 15.5% for the moderate/high IgG stratum. Variance differed in serum IgG concentration (P < .0001). Serum with higher IgG concentrations had more variance. Simulated CV for STP and IgG had homogeneity of variance for only 1 sera (P = .31). STP had a smaller CV compared to IgG for every serum (P < .0001). Estimating IgG concentration directly by RID or indirectly by STP lacks the precision that might affect diagnostic interpretation regarding a calf's absorption of maternal antibodies.

Colostrum Quality Assessment in Dairy Goats: Use of an On-Farm Optical Refractometer.

Failure of passive immunity transfer is one of the main causes of increased susceptibility to infectious agents in newborn kids. To ensure successful transfer of passive immunity, kids need to be fed high-quality colostrum, containing an adequate concentration of IgG. This work evaluated the quality of colostrum obtained in the first 3 days postpartum from Malagueña dairy goats. The IgG concentration in colostrum was measured using an ELISA as a reference method, and it was estimated by optical refractometer. Colostrum composition in terms of fat and protein was also determined. The mean concentration of IgG was 36.6 ± 2.3 mg/mL, 22.4 ± 1.5 mg/mL and 8.4 ± 1.0 mg/mL on days 1, 2 and 3 after parturition, respectively. Brix values obtained using the optical refractometer were 23.2%, 18.6% and 14.1% for days 1, 2 and 3, respectively. In this population, 89% of goats produced high-quality colostrum with IgG concentrations of >20 mg/mL on the day of parturition, but this percentage declined dramatically over the following 2 days. The quality of the fresh colostrum estimated with the optical refractometer was positively correlated with those obtained using ELISA (r = 0.607, p = 0.001). This study highlights the importance of feeding first-day colostrum to newborn kids and demonstrates that the optical Brix refractometer is suitable for the on-farm estimation of IgG content in colostrum.

Pineapple Sweetness Classification Using Deep Learning Based on Pineapple Images

In Thailand, the pineapple is a valuable crop whose price is determined by its sweetness. An optical refractometer or another technique that requires expert judgment can be used to determine a fruit's sweetness. Furthermore, determining the sweetness of each fruit takes time and effort. This study employed the Alexnet deep learning model to categorize pineapple sweetness levels based on physical attributes shown in images. The dataset was classified into four classes, i.e., M1 to M4, and sorted in ascending order by sweetness level. The dataset was divided into two parts: training and testing datasets. Training accounted for 80% of the dataset while testing accounted for 20%. This study's experiments were repeated five times, each with a distinct epoch and working with data that had been prepared. According to the experiment, the Alexnet model produced the greatest results when trained with balancing data across 10 epochs and 120 figures per class. The model's accuracy and F1 score were 91.78% and 92.31%, respectively.

High sensitivity lossy-mode resonance refractometer using low refractive index PFA planar waveguide

In this work a new strategy to improve the sensitivity of refractometers based on lossy-mode resonances has been proved. The proximity of the PFA (tetrafluoroethylene-perfluoro polymer) substrate refractive index to that of water has permitted to implement an optical refractometer with a sensitivity of 41,034 nm per refractive index unit (nm/RIU) for refractive indices ranging from 1.3318 to 1.3347. The work is supported with both theoretical and experimental results. This high sensitivity can be used for the development of LMR based chemical sensors and biosensors, where a low limit of detection is required, with the additional advantage of a simple disposable planar configuration.

Violet phosphorus-enhanced plug-and-play double-lane fiber optic surface plasmon resonance refractometer

The fiber optic surface plasmon resonance (SPR) technologies can directly detect the change of the refractive index on the surface of the sensor, caused by the interaction of biochemical molecules. Fiber optic SPR technologies have advantages of small size, low cost, no labeling, high sensitivity, and are easy to realize the miniaturization, multi-parameter, real-time and &lt;i&gt;in-situ&lt;/i&gt; detection. Two types of probe-type fiber optic SPR refractometers are constructed based on the novel two-dimensional nanomaterial, i.e., violet phosphorus (VP), the mature fabrication and characterization technologies. The fabrication processes of the fiber optic SPR refractometers are first introduced, and then the feasibility of the fabrication processes is verified via multiple characterization methods. In terms of the signal demodulation, the noise of the resonance spectrum is suppressed by the variational mode decomposition algorithm, and the resonance wavelength is interrogated and monitored in real time by the centroid method. The refractive index sensing performances of the near-field enhanced fiber optic SPR refractometers coated with different layers of VP are investigated. With the increase of the VP layer number, the resonance spectrum exhibits redshift and broadening and the sensitivity is enhanced. The refractive index sensing performance of the nearly guided wave fiber optic SPR refractometer is also investigated. In the low refractive index range of 1.33－1.34 corresponding to the refractive index of the low-concentration biological solution, the sensitivity and the figure of merit of the near-field enhanced fiber optic SPR refractometer with the sensing structure of fiber core/VP dielectric layer/Au layer/sample layer reach to 2335.64 nm/RIU and 24.15 RIU&lt;sup&gt;–1&lt;/sup&gt;, respectively, which are 1.31 times and 1.25 times higher than the counterparts of the single Au layer fiber optic SPR refractometer, respectively. The sensitivity and the figure of merit of the nearly guided wave fiber optic SPR refractometer with the sensing structure of fiber core/Au layer/VP dielectric layer/sample layer can reach to 2802.06 nm/RIU and 22.53 RIU&lt;sup&gt;–1&lt;/sup&gt;, respectively, which are 1.57 times and 1.16 times higher than the counterparts of the single Au layer fiber optic SPR refractometer. Finally, the near-field enhanced SPR and the nearly guided wave SPR are integrated into a single fiber probe to achieve the double-lane sensing. The fiber optic SPR refractometers developed in this study can realize the high-sensitivity, plug-and-play and double-lane detection of the combination of surface refractive index and volume refractive index. The probe-type refractometer also provides a new idea for detecting multi-type protein molecules and heavy metal ions in the biochemical field.

Evaluation of passive immunity absorption in Holstein Heifers

Colostrums considered of good and very high quality are considered colostrums with a BRIX of ≥25%, so the first weeks of a neonate's life are considered critical, showing a greater susceptibility to diseases. In this sense, the objective was to evaluate the quality of colostrum and the transfer of passive immunity in Holstein heifers. The experiment was carried out on a milk producing property, located in the municipality of Olho D'agua das Flores, Alagoas, from October 2021 to April 2022, where 181 crossbred heifers were used. To measure the quality of the colostrum, an optical Brix refractometer was used, if it showed a quality lower than 25% BRIX, this colostrum was corrected and offered to the calf. The collected blood was stored in a tube without anticoagulant and left to rest until the serum was obtained, later, a drop of this serum was applied to the refractometer prism and, similarly to colostrum, a reading was performed to determine the concentrations of proteins. totals. For Pearson's correlation study, correlation coefficient analysis (r) was performed, assuming intervals of -1 (negative linear association) and 1 (positive linear association). Serum protein showed a negative correlation with the time of colostrum supply after birth (r = -0.16) and positive with calf weight at birth (r = 0.15). The adequate program of colostrum and evaluation of transfer of passive immunity allied to the proper management collaborate for the success in the productive indexes of the properties.

An Assessment of the Accuracy of Digital and Optical Brix Refractometers for Estimating Passive Immunity in Beef Calves

This study was aimed at determining and comparing the diagnostic accuracy of digital and optical Brix refractometers (D-Brix and O-Brix, respectively) for the estimation of passive immunity status (

Genetic characteristics of colostrum refractive index and its use as a proxy for the concentration of immunoglobulins in Holstein cattle

BackgroundColostral concentration of immunoglobulins (Ig) is crucial for the passive transfer of antibodies from the cow to the new-born calf. Direct determination of Ig by the gold standard radial immunodiffusion method is demanding in terms of time and costs. For this reason, a refractometer is commonly used at the farm level for an indirect estimation of colostrum quality, which is given as the Ig concentration. In this study, colostrum samples were collected from 548 Italian Holstein cows within 6 h of calving. The refractive index (BRIX, %) of these samples was assessed using a portable optical refractometer, as well as the concentration of total protein, IgG, IgA, and IgM by radial immunodiffusion. A four-trait animal model was used to estimate genetic parameters for BRIX and the different immunoglobulin isotypes. A receiver operating characteristic analysis was carried out to evaluate the BRIX diagnostic accuracy.ResultsColostral BRIX was moderately heritable (0.26) and its genetic and phenotypic correlations with IgG (0.91, 0.78), IgA (0.57, 0.57), and IgM (0.71, 0.61) were all positive and of similar order, although the genetic correlations were generally higher than the phenotypic correlations. Low-quality colostrum samples, defined as those with an IgG concentration lower than 50 g/L, were accurately identified by the refractive index on the BRIX scale, with an area under the curve of 0.90.ConclusionsThe use of a refractometer is recommended on dairy farms to produce a proxy for colostral Ig concentration. BRIX is a useful phenotyping tool that can be used in cattle to improve the quality of colostrum for first feeding of calves through both traditional genetic and genomic strategies. Improving colostrum quality will reduce the incidence of failure of passive transfer of immunity in young stock.

Genetic parameters of colostrum and calf serum antibodies in Swedish dairy cattle

BackgroundA sufficient IgG content in the colostrum is essential for the newborn calf, as it provides passive immunity which substantially affects the probability of survival during rearing. Failure of passive transfer (FPT) occurs when a calf does not absorb enough antibodies from the colostrum and is defined by an IgG concentration in calf serum lower than 10 g/L. Apart from delayed access to colostrum, FPT can be due to a low production of IgG in the mother or poor IgG absorption by the calf. The aim of this study was to estimate the genetic background of antibody levels and indicator traits for antibodies in the colostrum and calf serum, and their correlation with milk production.ResultsColostrum data were available for 1340 dairy cows with at least one calving and calf serum data were available for 886 calves from these cows. Indicator traits for antibody concentrations were estimated using refractometry (a digital Brix refractometer for colostrum and an optical refractometer for serum), and enzyme-linked immunosorbent assays (ELISA) were used to determine the levels of total IgG and natural antibodies (NAb) of various antibody isotypes in the colostrum and calf serum. Colostrum traits had heritabilities ranging from 0.16 to 0.31 with repeatabilities ranging from 0.21 to 0.55. Brix percentages had positive genetic correlations with all colostrum antibody traits including total IgG (0.68). Calf serum antibody concentrations had heritabilities ranging from 0.25 to 0.59, with a significant maternal effect accounting for 17 to 27% of the variance. When later in life calves produced their first lactation, the lactation average somatic cell score was found to be negatively correlated with NAb levels in calf serum.ConclusionsOur results suggest that antibody levels in the colostrum and calf serum can be increased by means of selection.

A Versatile, Incubator-Compatible, Monolithic GaN Photonic Chipscope for Label-Free Monitoring of Live Cell Activities.

The ability to quantitatively monitor various cellular activities is critical for understanding their biological functions and the therapeutic response of cells to drugs. Unfortunately, existing approaches such as fluorescent staining and impedance‐based methods are often hindered by their multiple time‐consuming preparation steps, sophisticated labeling procedures, and complicated apparatus. The cost‐effective, monolithic gallium nitride (GaN) photonic chip has been demonstrated as an ultrasensitive and ultracompact optical refractometer in a previous work, but it has never been applied to cell studies. Here, for the first time, the so‐called GaN chipscope is proposed to quantitatively monitor the progression of different intracellular processes in a label‐free manner. Specifically, the GaN‐based monolithic chip enables not only a photoelectric readout of cellular/subcellular refractive index changes but also the direct imaging of cellular/subcellular ultrastructural features using a customized differential interference contrast (DIC) microscope. The miniaturized chipscope adopts an ultracompact design, which can be readily mounted with conventional cell culture dishes and placed inside standard cell incubators for real‐time observation of cell activities. As a proof‐of‐concept demonstration, its applications are explored in 1) cell adhesion dynamics monitoring, 2) drug screening, and 3) cell differentiation studies, highlighting its potential in broad fundamental cell biology studies as well as in clinical applications.

Diagnostic characteristics of refractometry cut-off points for the estimation of immunoglobulin G concentration in mare colostrum.

Feeding foals with poor quality colostrum predisposes them to failure of passive transfer (FPT). FPT is a major risk factor for neonatal infections. To assess the optimal cut-offs for the optical (OR) and digital (DR) refractometer and determine their accuracy for poor quality colostrum diagnosis. A diagnostic validation study. Eighty-one colostrum samples and sera were collected from broodmares and their neonatal foals, respectively. Colostral and serum IgG concentrations were measured by radial immunodiffusion (RID), DR and OR. Correlation coefficients were calculated. ROC curves were generated to identify optimal cut-offs for the refractometers and their diagnostic characteristics were evaluated. The optimal cut-offs for DR and OR were ≤23.75% and 23.9%, respectively. The sensitivity and specificity of the DR were 93.3% (95% CI: 66.0-99.7) and 87.9% (95% CI: 77.0-94.3) to detect colostral IgG <60g/L, respectively. The sensitivity and specificity of the OR were 93.3% (95% CI: 66.0-99.7) and 81.8% (95% CI: 70.0-89.9), respectively. DR and OR had negative predictive values of 98.3% (95% CI: 89.7-99.9) and 98.2% (95% CI: 89.0-99.9), respectively, whilst positive predictive values were lower. No maternal variable, including breed, significantly influenced colostral IgG concentrations. Fifteen out of 81 colostrum samples had IgG <60g/L. FPT and PFPT were diagnosed in 4/81 and 10/81 foals, respectively. Nine out of 14 animals with FPT/PFPT suckled colostrum with IgG <60g/L. A moderate correlation (rs 0.542; P=.01) was observed between IgG concentrations measured by RID in sera and colostrum. A smaller number of samples than the size requirement based on a priori estimate of specificity and the low prevalence of poor quality colostrum. The method has the potential to reliably differentiate between good and poor quality colostrum. Assessing colostrum quality by refractometry may be an indicator of passive transfer of immunity.

Validation of Brix refractometer to estimate immunoglobulin G concentration in goat colostrum.

Background and Aim:Immunoglobulin G (IgG) concentration is high in goat colostrum, particularly in the first few hours after parturition, and this is important for the kid’s immunity and growth. IgG levels vary depending on several factors, including breed, disease status, colostrum management, handling, and collection time postpartum. A handheld optical refractometer, an affordable instrument that is simple to use in the field, is used widely in dairy farms to measure total solids. However, it can also be applied to estimate colostrum IgG content on the basis of comparison with standard measurement methods, usually radial immunodiffusion. Studies comparing %Brix values in relation to IgG concentration measured using enzyme-linked immunosorbent assay (ELISA) in goats are limited. The present study aimed to evaluate the use of a handheld optical Brix refractometer for the measurement of IgG concentration in goat colostrum, compare results with those using ELISA, and estimate the %Brix cutoff value equating to low-quality colostrum.Materials and Methods:Colostrum samples were collected on day 0 from 21 goats (nine Black Bengal, six Saanen, and six of their crossbred offspring) and were frozen. Subsequently, they were analyzed for IgG concentration using a goat-specific ELISA test and Brix percentage using a handheld refractometer. The optimum %Brix cutoff value for the evaluation of colostrum quality was evaluated.Results:The mean IgG concentration and %Brix in colostrum were 10.60±0.64 mg/mL and 25.0±0.9, respectively. There was a significant (p<0.01) correlation between %Brix and IgG concentration. For an IgG concentration of 6.9 mg/dL, the cutoff value for %Brix was 18.5, equating to high specificity (100%) but low sensitivity (50%). A higher %Brix cutoff value of 21.5 showed high specificity (95%) and high sensitivity (100%).Conclusion:A Brix refractometer can be used to estimate goat colostrum quality with a proposed %Brix cutoff value of <18.5%-21.5% for poor-quality colostrum.

Innovation of Women Farmers: A Technological Proposal for Mezcalilleras’ Sustainability in Mexico, Based on Knowledge Management

Currently, technology usage is a fundamental asset for creating, developing, and implementing innovations; however, these are not available to everyone, which is accentuated in women with agricultural occupations. The present study develops a proposal of technologies for mezcalilleras’ sustainability from Oaxaca, Mexico, based on a knowledge management methodology, through the application of questionnaires in face-to-face sessions, field visits, and statistical analysis to explore the imbalances enclosed in the agave–mezcal activity seen as its problems, failures, and barriers, as well as its correlation with the identified technological routes. The results reveal that a technological platform creation, the fabrication of fiber optic refractometer, a metal roof construction, the design of a horizontal distiller–fractionator, the employment of metal containers and production of glass bottles, and the generation of a software and an application, are the suitable technologies, according to the mezcalilleras’ requirements. This proposal can be important for academics, policymakers, and producers who wish to revitalize traditional knowledge of the small-scale sectors in Mexico through new ways of interaction with external agents and customers, new ways of production, and previous years’ production analysis.