Hyperspectral imaging as an effective tool for prediction the moisture content and textural characteristics of roasted pistachio kernels

The objective of this study was to develop calibration models for prediction of moisture content and textural characteristics (fracture force, hardness, apparent modulus of elasticity and compressive energy) of pistachio kernels roasted in different conditions (temperatures 90, 120 and 150 °C; times 20, 35 and 50 min and air velocities 0.5, 1.5 and 2.5 m/s) using Vis/NIR hyperspectral imaging and multivariate analysis. The effects of different pre-processing methods and spectral treatments such as normalization [multiplicative scatter correction (MSC), standard normal variate transformation (SNV)], smoothing (median filter, Savitzky–Golay and Wavelet) and differentiation (first derivative, D¹ and second derivative, D²) on the obtained data were investigated. The prediction models were developed by partial least square regression (PLSR) and artificial neural network (ANN). The results indicated that ANN models have higher potential to predict moisture content and textural characteristics of roasted pistachio kernels comparing to PLSR models. High correlation was observed between reflectance data and fracture force (R²?=?0.957 and RMSEP?=?3.386) using MSC, Savitzky–Golay and D¹, compressive energy (R²?=?0.907 and RMSEP?=?15.757) using the combination of MSC, Wavelet and D¹, moisture content (R²?=?0.907 and RMSEP?=?0.179) and apparent modulus of elasticity (R²?=?0.921 and RMSEP?=?2.366) employing combination of SNV, Wavelet and D¹, respectively. Moreover, Vis–NIR data correlated well with hardness (R²?=?0.876 and RMSEP?=?5.216) using SNV, Wavelet and D². These results showed the capability of Vis/NIR hyperspectral imaging and the central role of multivariate analysis in developing accurate models for prediction of moisture content and textural properties of roasted pistachio kernels.     

Design,fabrication, and testing of a pulper for Kendu (Diospyros melanoxylon Roxb.)

Kendu (Diospyros melanoxylon Roxb.) is a minor forest produce commercially grown in India for its leaves for traditional cigarette‐making. Though the fruit has high nutritive value, it is not used for diet purpose. This may be due to the difficulty in extracting the pulp. To address this issue, a brush type pulping machine was developed for Kendu. The pulper consists of the feed hopper, feed rollers, barrel housing, stainless steel cylinder, and a shaft with two nylon brushes. The feed rollers are provided with conical spikes to compress and shear the hardcover of the fruit. The pulper has an overall dimension of 1.2 m × 0.75 m × 0.40 m and a throughput of 50 kg/hr. The housing field area of the machine is 1.130 m². The overall extraction efficiency of the pulper is 78.36% at an optimized speed and feed rate of 260 rpm and 2.5 kg/min, respectively.

Practical applications

A small‐scale pulper has been designed and fabricated for Kendu fruit, an underutilized minor forest produce. As such, there is no machine to extract pulp from Kendu. Manual removal of hardcover and seeds and separation of the pulp are labor intensive and time consuming. This problem limits the potential use of the fruit. The designed machine will serve as a milling cum pulping machine and would address the issue of underutilization of the fruit. The highly nutritious pulp thus extracted by the pulper can be further processed to various value‐added products. This would certainly increase the commercial use of the fruit and boost income generation to support the livelihood of the people. The designed pulper can also be used for other fruits of similar structure.     

Studies on air permeability of multi-constituent nonwovens

In this work, a series of multi-constituent nonwovens possessing multi-modal fiber diameter distribution was prepared and the air permeability of such nonwoven structures was measured. This approach was extended to bi-constituent nonwovens consisting of fibers with bi-modal diameter distribution and mono-constituent nonwovens composed of fibers with mono-modal diameter distribution. The multi-constituent nonwovens exhibited highest air permeability, followed by the bi- and mono-constituent nonwovens for the same mean fiber diameter. This was explained in terms of the mean pore diameter of the multi-, bi-, and mono-constituent nonwoven structures. An analytical expression of mean fiber diameter of multi-constituent nonwoven structures was derived. The square of the mean fiber diameter in the multi-constituent nonwovens was found to be the harmonic mean of the volume-weighted square of the mean fiber diameter of the individual constituents. The mean fiber diameter coupled with Kozeny–Carman equation was found to predict the air permeability of the multi-, bi-, and mono-constituent nonwovens very well. It was observed that the mono-constituent nonwoven displayed the highest value of Kozeny–Carman coefficient, followed by the bi- and multi-constituent nonwovens.     

Quantitative risk assessment of listeriosis due to consumption of raw milk

The objectives of this study were to estimate the risk of illness for raw milk consumers due to Listeria monocytogenes in raw milk sold by permitted dealers, and the risk for people on farms who consume raw milk. Three scenarios were evaluated for raw milk sold by dealers: raw milk purchased directly from bulk tanks, from on-farm stores, and from retail. To assess the effect of mandatory testing of raw milk by regulatory agencies, the number of listeriosis cases per year was compared where no raw milk testing was done, only a screening test to issue a permit was conducted, and routine testing was conducted and milk was recalled if it was L. monocytogenes positive. The median number of listeriosis cases associated with consumption of raw milk from bulk tanks, farm stores, and retail for an intermediate-age population was 6.6 × 10(-7), 3.8 × 10(-5), and 5.1 × 10(-5) cases per year, respective ly. In populations with high susceptibility, the estimated median number of cases per year was 2.7 × 10(-7) (perinatal, i.e., pregnant women and their fetuses or newborns) and 1.4 × 10(-6) (elderly) for milk purchased from bulk tanks, 1.5 × 10(-5 ) (perinatal) and 7.8 × 10(-5) (elderly) for milk from farm stores, and 2.1 × 10(-5) (perinatal) and 1.0 × 10(-4) (elderly) for milk from retail. For raw milk consumed on farms, the median number of listeriosis cases was 1.4 × 10(-7) cases per year. A greater risk of listeriosis was associated with consumption of raw milk obtained from retail and farm stores as compared with milk obtained from bulk tanks. This was likely due to additional time-temperature combination steps in the retail and farm store models, which increased the chances for growth of L. monocytogenes in raw milk. A close relationship between prevalence of L. monocytogenes in raw milk and the values of disease incidence was observed. Hence, a reduction in the number of cases per year in all populations was observed when a raw milk-testing program was in place, especially when routine testing and recalling of milk was conducted.     

Highly Efficient,Bright, and Stable Colloidal Quantum Dot Short‐Wave Infrared Light‐Emitting Diodes

Unbalanced charge injection is deleterious for the performance of colloidal quantum dot (CQD) light‐emitting diodes (LEDs) as it deteriorates the quantum efficiency, brightness, and operational lifetime. CQD LEDs emitting in the infrared have previously achieved high quantum efficiencies but only when driven to emit in the low‐radiance regime. At higher radiance levels, required for practical applications, the efficiency decreased dramatically in view of the notorious efficiency droop. Here, a novel methodology is reported to regulate charge supply in multinary bandgap CQD composites that facilitates improved charge balance. The current approach is based on engineering the energetic potential landscape at the supra‐nanocrystalline level that has allowed to report short‐wave infrared PbS CQD LEDs with record‐high external quantum efficiency in excess of 8%, most importantly, at a radiance level of ≈5 W sr^?1 m², an order of magnitude higher than prior reports. Furthermore, the balanced charge injection and Auger recombination reduction has led to unprecedentedly high operational stability with radiance half‐life of 26 068 h at a radiance of 1 W sr^?1 m^?2.