Effect of temperature difference on the aroma and quality of carrots processed through microwave drying combined with hot air drying

Online Machine Vision-Based Modeling during Cantaloupe Microwave Drying Utilizing Extreme Learning Machine and Artificial Neural Network

Online microwave drying process monitoring has been challenging due to the incompatibility of metal components with microwaves. This paper developed a microwave drying system based on online machine vision, which realized real-time extraction and measurement of images, weight, and temperature. An image-processing algorithm was developed to capture material shrinkage characteristics in real time. Constant-temperature microwave drying experiments were conducted, and the artificial neural network (ANN) and extreme learning machine (ELM) were utilized to model and predict the moisture content of materials during the drying process based on the degree of material shrinkage. The results demonstrated that the system and algorithm operated effectively, and ELM provided superior predictive performance and learning efficiency compared to ANN.

Effect of heat and pulsed electric field treatment on the physicochemical and nutritional properties of carrots

BACKGROUND

Carrots are widely used in home cooking and vegetable processing industries because of their high nutritional value. However, different processing methods may produce a negative impact on carrot texture and nutrition quality. Therefore, the development of better processing methods to preserve the texture and nutrition quality of carrots will be beneficial to the carrot industry.

RESULTS

The effects of heat and pulsed electric field (PEF) treatments with different heat temperatures (T) and holding time (t_h ) on comprehensive changes in thermal efficiency profiles, and physicochemical (color, hardness, cell structural damage) and nutritional (releasable β-carotene contents) properties of carrots were studied. In addition, electrical conductivity (σ) and soluble matter contents (°Brix) were determined for the heat-treated extracts. The value of total color difference (∆E) and cell structural damage index (Z) of carrots, σ and °Brix of extracts all increased with increasing T and t_h under different heat experimental conditions, whereas the value of cutting force (F) presented an opposite tendency and content of releasable β-carotene decreased after t_h  > 2 min at T = 100 °C.

CONCLUSION

The results show that PEF heating is beneficial in preventing changes in physicochemical and nutritional properties of carrots compared to traditional heat treatment. PEF has potential as a heating technology in the food industry. © 2022 Society of Chemical Industry.