Pineapple is a highly nutritious and widely consumed fruit in Bangladesh, yet postharvest losses continue to increase due to inadequate preservation technology. This study is aimed at developing and evaluating a natural convective solar dryer as a sustainable solution to reduce these losses while preserving fruit quality. The dryer’s performance was assessed by measuring drying temperature, solar radiation, and moisture reduction across treated and untreated pineapple samples. During the drying process, the average temperature within the dryer reached 40.73 ± 6.79°C, with solar radiation averaging 254.67 ± 141.50 W/m ² and an observed 12.6°C temperature difference between the dryer chimney and ambient air. Results showed a final moisture content of 19% and 21% (wet basis) for treated and untreated samples, respectively, in the solar dryer, compared to 46.57% and 35.06% in open sun drying. The nutritional analysis indicated a significant retention and enhancement of vitamin, protein, and mineral content in dried samples. Consumer sensory evaluations confirmed the high acceptability of the solar‐dried pineapple, demonstrating that this solar dryer is technically effective, eco‐friendly, and well suited for small‐scale farmers in rural Bangladesh.

Research on packaged fruits has seen a notable upturn primarily driven by consumers’ desire for fruit safety and quality across the distribution network. This study examined the effectiveness of hyperspectral imaging (HSI) combined with chemometrics to assess the internal quality of packaged and non-packaged fresh fruits. Visible–near-infrared (Vis-NIR; 400–1000 nm) and short-wave infrared (SWIR; 1000–2500 nm) hyperspectral images of apples and plums were captured using 200 samples for each fruit across three groups—plastic wrap (PW), polyethylene terephthalate (PET) box, and non-packaged (NP)—for the prediction of soluble solid content (SSC), moisture content (MC), and pH. A partial least square regression (PLSR) model demonstrated promising results on SSC and MC across all sample groups in both Vis-NIR and SWIR, with performance ranked NP > PW > PET. Calibration and prediction coefficients of determination (R²) exceeded 0.82, 0.80, and 0.79, with root mean square errors (RMSE) less than 0.57, 0.59, and 0.59 for NP, PW, and PET, respectively. This research outcome confirmed the suitability of HSI as a critical instrument for predicting the composition of fresh fruits inside plastic packaging, offering a quick and non-invasive approach for quality evaluation in supply chains.

Drying is an effective means of reducing moisture content of perishable fruit and vegetables to a safe storage level and reduce post harvest loss. This study was conducted to evaluate a solar tunnel dryer for drying cabbage in comparison to traditional open sun drying at the advanced drying lab of the Department of Farm Power and Machinery, Bangladesh Agricultural University, Mymensingh. Salt pre-treated cabbage was used for drying inside the dryer and open sun drying. The parameters like solar radiation, temperature, relative humidity, and moisture content were measured using standard instruments during the experiments. The results showed that the maximum peak temperature inside the drying chamber was 45 °C during mid-day (12 pm) when solar radiation was 600 w/m2 and in an average inside temperature was approximately 30°C to 40°C in a full sunny day (9:00 AM to 04:00 PM) when average solar radiation was 321±115 W/m2. The moisture content of sliced cabbage was reduced initially 94.42, 90.18, and 92.24 % (w.b.) to 4.85, 15.84, and 15.71% (w.b.), and drying time of the dryer was 28, 21, and 19 hours in 1st, 2nd, and 3rd trials, respectively. The drying rate and drying efficiency were found 0.15 kg/hr. and 8.22 %, respectively in tunnel dryer and 0.02 kg/hr. and 3.38 %, respectively in open sun drying. The color and texture of the solar tunnel dried cabbage were better than the open sun drying method. Further experiments are required for estimating drying capacity with the operating cost of the solar tunnel dryer when the dryer will be used with its full capacity.

Solar drying is an easy and environmentally friendly way of food preservation. The use of a solar dryer for multicrop may also make this technology cost‐effective. In fact, the performance evaluation of a solar dryer for different fruits and vegetables promotes the usability of a dryer for crops. Hence, in this study, a newly developed natural convection solar dryer has been evaluated for drying cabbage. Cabbage samples were pretreated with a brine solution (with 5% [ w / w ] NaCl) followed by blanching. Pretreated samples were dried both in the dryer and open sun. Control samples were also dried in the solar dryer and open sun. The cabbage was dried in single and multilayer arrangements, maintaining thin layer drying thickness. Temperature distribution in and outside of the dryer was also investigated during the experiment, both spatially and temporally. The acceptability of dried cabbage was checked using a 9‐point hedonic scale test. The experimental value of the moisture ratio was fitted with four different thin layer drying models—Newton, Page, modified Page, and Henderson. The drying air temperature consistently exceeded the ambient temperature by approximately 1°C–35°C, depending on the intensity of solar radiation. Drying efficiency for single‐layer and multilayer arrangements were 25.25% and 43.57%, respectively. Hence, multilayer drying of cabbage in the dryer can be an effective means of drying with higher efficiency. From the acceptability test, it was found that solar dried pretreated cabbage was mostly liked. The best fitted model was the Page model for both single and multilayer drying. Performance evaluation for multilayer drying of other fruits and vegetables might increase this dryer’s usability.