The walnut varieties in China are rich, the planting area in the country is wide, and the yield ranks at the forefront of the world Walnut kernel is the most important application part of the walnut fruit An in-depth study found that the by-products of walnut, such as green husk and walnut shell, also have great application potential and are cheap raw materials for the extraction of important medical ingredients and the production of industrial products However, the by-products are often burned or discarded as waste during processing, which not only wastes resources but also causes environmental pollution To realize the high value-added application of the walnut fruit, a deep processing of each part of the walnut should be considered Preliminary processing is the key link before walnuts enter the field of intensive processing and consumption The advanced level of the required technological equipment can help to determine the quality of the walnut products The preliminary processing of walnuts in China is mainly divided into six steps: green husk removal, walnut drying, walnut size classification, walnut shell-breaking, walnut shell–kernel separation, and walnut kernel skin removal This paper starts with a presentation of the importance of each link and the existing bottleneck Then, the paper systematically discusses the analysis of the current situation and the development of devices required for each link The working mechanism of each link type and its influence on the design of a corresponding device are summarized On the basis of the corresponding working mechanism, this study classifies and summarizes the characteristics of the core mechanism of the devices for each preliminary process link; then, it evaluates and analyzes the existing typical mechanical devices according to their types Finally, the influence rule of the various devices for each link in the preliminary processing is analyzed as a means of ensuring high-quality walnuts

Walnut Fruit Processing Equipment: Academic Insights and Perspectives

CFD modeling of air flow distribution in rice bin storage system with different grain mass configurations

Drying and decontamination of raw pistachios with sequential infrared drying, tempering and hot air drying

This study was aimed to develop a sequential infrared and hot air (SIRHA) drying method for whole almonds and evaluate its effectiveness on decontamination of almonds. Wet almonds with hull and shell were dried using different time-combinations of infrared (IR) radiation and hot air (HA) to determine the optimum drying conditions. Almonds were inoculated with Enterococcus faecium, a surrogate for Salmonella enterica. The SIRHA drying (1h IR at 70 °C and 2h HA) reduced the moisture content of almonds to 7% in 3 h, with a saving of 2 h (40%) of drying time compared with HA drying alone. The population sizes of E. faecium showed the largest size reductions of 4.69 ± 0.71, 1.82 ± 0.39, 1.52 ± 0.31 log CFU/nut on hulls, shells and kernels, respectively, after SIRHA drying combined with tempering (T) (2h IR with 2h T and 1h HA). The peroxide value and free fatty acids content of almond oil samples from all drying treatments were within accepted level for the almond industry.

Feasibility of using sequential infrared and hot air for almond drying and inactivation of Enterococcus faecium NRRL B-2354

Effect of step-down temperature drying on energy consumption and product quality of walnuts

. The walnut industry is faced with an urgent need to improve post-harvest processing efficiency, particularly drying and dehulling operations. This research investigated the feasibility of dry-dehulling and infrared (IR) pre-drying of walnuts for improved processing efficiency and dried product quality. Freshly harvested walnuts (ethephon and non-ethephon treated) with whole and partly-attached hulls were dehulled using a test device to determine dry-dehulling time and frequency. The physical dimensions of walnuts without, with partly-attached, and with whole hulls were determined. In-shell walnuts of high (43%, w.b.) and low (18%, w.b.) moisture were pre-dried with IR for 2, 3, and 4 min followed by hot air (HA) drying at 43°C for up to 24 h and effects on drying rate and product quality were studied. Based on results, walnuts with whole and partly-attached hulls could be dry-dehulled to achieve over 90% dehulled nut in 45 and 15 s, respectively. Ethephon treatment had no significant influence on dry-dehulling of walnuts with partly-attached hulls. Contrarily, Ethephon-treated walnuts with whole hulls had dehulled nut percentage higher than untreated ones. Walnuts without, with partly-attached, and with whole hulls could be separated based on axial dimensions. IR pre-drying improved walnut drying rate. Up to 7% moisture reduction for high moisture nuts was achievable in 240 s of IR pre-drying with nut center temperature relatively below 43°C in the first 150 s. IR pre-drying for 180 s followed by HA drying had no effect on the quality of processed products compared with HA. The studied approaches have potential to improve processing efficiency and quality of dried walnuts.

Infrared Pre-Drying and Dry-Dehulling of Walnuts for Improved Processing Efficiency And Product Quality

. Determination of dockage of freshly harvested rice is crucial for precise development of a universal rice shrink chart. The objectives of this research were to determine the effect of different factors, including rice variety, farm location, harvest moisture and time, drying, dropping, weather events such as wind and rainfall, and type of harvester, on dockage. The study was conducted during two consecutive rice harvesting seasons. The dockage of freshly harvested rice with moisture content (MC) ranging from 18% to 27% wet basis (w.b.) varied between 0.2% and 2.0% with averages of 0.92% and 0.79% in 2010 and 2011 harvest seasons, respectively. The corresponding averages of dockage of dried rice with MC of 14±1% (w.b.) were 0.78% and 0.65%, which were lower than those of freshly harvested rice. There were no significant differences (p>0.05) in dockage among the studied rice varieties. It was also observed that dockage was not significantly affected (p>0.05) by the harvest MC, geographical location and dropping from certain height. However, wind and rainfall events significantly (p

Ruipeng Fu

Papers

Infrared Pre-Drying and Dry-Dehulling of Walnuts for Improved Processing Efficiency And Product Quality

Determination of Dockage for Accurate Rough Rice Quality Assessment