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Excess nitrogen fertilizer use leads to vegetables with high amounts of nitrate content. Consumption of vegetables with high amounts of nitrate is carcinogenic to human beings. In this study, fenugreek plants were grown under varying nitrogen fertilizer doses (0, 50, 100, 150, 200, 250, 300, 350 and 400 kg N/ha). A Vis-NIR hyperspectral imaging (HIS) camera captured images of fenugreek leaves within the 398–1,003 nm spectral range. The spectral data were pre-processed using different pre-processing techniques before the model development. Partial least-squares regression (PLSR) models were constructed with complete spectral data and selected wavelengths. The performance of the PLSR model decreased with pre-processed spectral data, and there was no significant difference compared to the model constructed with raw spectral data (R 2 CV = 0.915, SECV = 591.933, slope = 0.518 and RPDCV = 1.421). The wavelengths 411, 435, 466, 558, 669, and 720 nm were selected as feature wavelengths for representing nitrate content in fenugreek leaves. The performance of the PLSR model constructed with feature wavelengths (SECV = 648.672; RPDCV = 1.482; R 2 CV = 0.869) was non-significant compared with the model developed with raw complete spectral data (SECV = 591.933; R 2 CV = 0.915 and RPDCV = 1.421). Using the complete raw spectral data, the spatial distribution images of nitrate content in fenugreek leaves indicated that the nitrate content was concentrated near and along the midrib up to the apex. The overall results obtained in the present study suggest that VIS-NIR HSI, along with suitable chemometric techniques, can be used for rapid assessment of nitrate content in fenugreek leaves.

Postharvest losses contribute to food shortages and ongoing food insecurity. Value addition in each aspect of agricultural produce creates more quality and adequate demand for the products. However, the growing market demand for quality and consistency in supply requires resources and necessary technical skills. There is a poor linkage between Research and Development institutions and the agro-value addition industry. Shortage of postharvest and value addition technical specialists and inefficient knowledge transfer from research stations to extension services are some constraints for needed outreach activities. Effective extension and training play a vital role in building capacity along the value chain by encouraging proper postharvest activities. In this article, the current postharvest value addition challenges are discussed with a specific focus on Oman. Furthermore, the strategies to be undertaken to enhance value addition processing and the need for increased institutional capacity building and technology transfer to achieve sustainability are discussed. It was recommended that targeted involvement be aimed at for better support for agricultural value addition in Oman.

One of the most crucial factors in determining the consumer acceptability of processed or non-processed food products is their textural characteristics. Textural properties of food items can be created during processing by different techniques, one of which is drying. Drying which is one of the most widely used preservation methods of food products can extend their shelf life and generate unique sensory characteristics. The complicated process of drying is characterized by massive deformations while simultaneously transferring heat and moisture. Texture parameters of the dried food products vary depending on the type of dried food product (fruit and vegetables, grain and cereals, meat and marine), including the final volume, porosity, crust formation, and bulk density. Thus, this review focused on the examination of the textural characteristics of dried food items, the impact of the drying process, and the applied method on textural parameters. This study has also investigated the importance of pretreatment methods in improving the textural properties and quality of dried products. Furthermore, this review also considers the importance of modeling for texture prediction, discussing the different modeling approaches and their principles and applications. Recent applied nondestructive methods for textural analysis have been discussed in terms of application and performance. [ABSTRACT FROM AUTHOR]

Foxtail millet is a type of minor millet that has nutritional‐rich characteristics. The bran layer in millets contains a considerable amount of antinutritional properties, and grain/flour/product spoilage occurs due to fat in the bran layer. Therefore, the removal of bran from millets can enhance their shelf life. Bran removal from foxtail millet is challenging because of its tiny size. Hence, the study targeted optimizing polishing process parameters for foxtail millet. The effect of process variables such as grain moisture content (8%–16% w.b.), emery roller speed (800–2400 rpm), and polishing time (1–8 min) on polishing characteristics (degree of polishing, head yield, middling yield, and broken content) and proximate composition (protein, fat, crude fiber, ash, and carbohydrate contents) of foxtail millets was studied using the central composite rotatable design (CCRD). Emery roller speed and polishing time significantly affected all responses (p < 0.01). In contrast, grain moisture content had a significant effect only on the degree of polishing (p < 0.05), head, and middling yields (p < 0.01). A numerical optimization technique was adopted to optimize the process parameters of the polisher. The optimum operating conditions were 10% grain moisture content, 1650 rpm of emery roller speed, and 2 min of polishing time. A validation study conducted at optimized conditions revealed no significant difference between the predicted and actual values of responses and considerably less broken content (9.26%). The results of the present study indicate that machinery modified and processes optimized during the study are fairly accepted and can be used to upscale the machine for industrial use. [ABSTRACT FROM AUTHOR]

The quality of vegetables depends upon the preharvest and postharvest practices. The preharvest practices include type, amount, form of fertilizers, harvesting period, growing season, and conditions that influence the yield of the crop and affect its chemical, biochemical, and mechanical properties. Moreover, postharvest practices such as storage conditions and processing methods also affect the quality of vegetables. Therefore, the present study was conducted to study the effect of different doses of nitrogen fertilizer (0–400 kg·N/ha) and storage conditions on the quality attributes of spinach leaves such as respiration rate, physiological loss in weight (PLW), chromatic properties, chlorophyll, puncture strength, TSS, pH, and nitrate during the storage studies. The respiration rate of leaves decreased with an increase in fertilizer dose. The a∗and ΔE values of spinach leaves significantly (p < 0.01) increased with an increase in storage temperature (T) and storage time (t) and decreased significantly (p < 0.01) with an increase in fertilizer dosage (F). The puncture strength (PS) of leaves significantly (p < 0.01) decreased with an increase in F, T, and t. The T, t, and their interaction had a significant (p < 0.05) negative effect on the chlorophyll content of spinach leaves for all treatments. However, the T, t, and their interaction had a significant (p < 0.01) positive effect on pH and PLW and a negative effect on the nitrate content. The colour change, nitrate, and chlorophyll degradation were higher with storage time for leaves which have a higher amount of nitrate content initially. The TSS, pH, PLW, and mechanical properties degradation were higher with storage time for leaves that initially had a lower amount of nitrate content. Therefore, application of the recommended dosage (as per the soil nutrient status) of nitrogen fertilizer can produce leaves with minimum nitrate content, and storage of leaves under refrigerated conditions can enhance the shelf life. [ABSTRACT FROM AUTHOR]

Cucumbers are a popular vegetable consumed worldwide and are known for their nutritional value, containing carbohydrates, antioxidants, vitamin C, etc. The abundance of a high moisture content is correlated to cucumber perishability, which encourages investigation into ways to maintain its quality and increase shelf-life. This study was carried out to determine the effect of a moringa oil–beeswax coating on the quality of fresh cucumber at different storage temperatures for 27 days of storage. Freshly harvested cucumbers were divided into two groups: the first group was coated with the moringa oil–beeswax edible coating, while the other one was not coated (control). Each group was divided into three other subgroups, for storage at 4, 10, and 22 °C. Different quality parameters, including weight loss, color change, firmness, total soluble solid (TSS), vitamin C, and pH, were evaluated. The findings showed that the weight loss of cucumber was highly increased in non-coated samples stored at high temperature. After 27 days of storage, the highest and lowest weight reduction % were recorded for non-coated cucumbers stored at 22 °C (38.09%) and moringa oil–beeswax-coated cucumbers stored at 10 °C (12.35%), respectively. Color analysis revealed that coating had a significant impact on color values, with distinct patterns in lightness, redness-greenness, and yellowness values for both treatments at various temperatures and days. The lightness values showed minimal fluctuations and stabilized at 13.65 at both 4 °C and 10 °C. Temperature and coating had a significant impact on pH levels, with the coating potentially exhibiting a protective effect on pH stability, particularly at lower temperatures (4 °C). Additionally, both groups' total acidity levels held steady over time and at various temperatures, with the coating having a highly significant effect on total acidity levels. The amount of vitamin C varied significantly with temperature and storage period, but the coating did not affect vitamin C content. At 22 °C, there were notable variations in the vitamin C content over the storage period, with a final value of 37.7 mg/L on coated samples. Temperature and the duration of storage (p < 0.05) had a significant impact on the levels of total soluble solids (TSS), whereas firmness values changed significantly over the storage period only. Moringa oil–beeswax edible coating has the potential to preserve the nutritional value and quality attributes of cucumber. [ABSTRACT FROM AUTHOR]

Summary: The quality (i.e. the degree of excellence and acceptance to the consumer) evaluation and safety of fruit and other agricultural products is by far the main challenging task in the food industries. Hence, the development of efficient non‐invasive, real‐time and rapid‐quality assessment tools and techniques is the need of the hour. This review paper aims to provide the basic or fundamental knowledge regarding the principle, potential and application of near‐infrared imaging‐based computer vision systems. Non‐invasive technologies, based on optical properties, are the most applicable and important for real‐time quality assessment. Absorption, reflection and scattering before the transmission of incident light are phenomenon properties of biological materials. The principle and application of NIR imaging (i.e. medical imaging) in agriculture for quality detection were studied from various published research papers. Thus, collected pieces of information are summarised, concluded and discussed in a unique way in this report. The NIR spectrum of electromagnetic waves has some basic benefits of light penetration into the upper layer and makes visualisation of the targeted area of objects. Several studies have proved that the non‐destructive system based on visible and non‐visible imaging in combination has a significant role in quality defect detection in fruits. In NIR imaging, the artefacts caused by light illumination can be reduced and it will help in the visualisation of biological tissues and hidden defects just below the peel. [ABSTRACT FROM AUTHOR]

In this study, the finite volume method was used to evaluate the thermal performance of a flat-plate solar collector used to dry agricultural crops. A 3D numerical model was created and used to predict the outlet air velocities and temperatures for three inlet air velocities. When compared with experimental measurements, the numerical predictions showed good agreement under all testing conditions. Then, the numerical model was used to predict the internal airflow and heat transfer characteristics of the collector. The internal baffles were found to increase the dwell time and efficiency but also promote flow separation, which resulted in flow loss. In addition, the collector has a transparent cover that results in a substantial heat loss, which can be mitigated by adding a vacuum gap between the flow inside the collector and the cover. Increasing the flow rate increased the heat loss and decreased the heat uptake, which decreased the temperature difference between the inlet and outlet of the collector. Because the heat was lost through long-wavelength radiation via the transparent cover and sidewalls, coating the absorber plate with black matte paint to increase the solar radiation absorption coefficient did not improve the drying performance. [ABSTRACT FROM AUTHOR]