Effect of pulsed‐vacuum, hot‐air, infrared, and freeze‐drying on drying kinetics, energy efficiency, and physicochemical properties of Ginkgo biloba L. seed

Abstract

In this research, Ginkgo biloba L. seeds (GBS) were freeze-dried, infrared-dried, hotair dried, and pulsed-vacuum dried. A detailed analysis of their drying kinetics (drying curve, drying rate curve, effective moisture diffusivity, mathematical modeling), shrinkage and energy efficiency (specific moisture extraction, specific energy consumption), and physicochemical properties (soluble solids, total sugar, reducing sugar, ascorbic acid, phenolics, and tannins) were performed. Results showed drying methods had various effects on different indexes and were confirmed by principal component analysis. The drying process occurred in the falling-rate period. The effective moisture diffusivity values amongst various drying methods ranged from 3.5 × 10 −8 to 7.6 × 10 −8 m 2 /s, which were within the normally expected range for food materials. The exponential model best fitted the experimental results for drying with coefficient of determination (R 2 ) > .981 and root mean square error, sum of square error, and reduced chi-square closer to zero than the parabolic and inverselogarithmic (Log3p1) models. The freeze-dried GBS had the highest nutritional (statistically the same with the fresh GBS) and lower shrinkage; nevertheless, it had the lowest moisture extraction rate and the highest energy consumption. Hot-air dried GBS had the highest shrinkage and lowest nutritional retention. Infrared-dried GBS was superior with the highest non-tannic phenolic, proanthocyanidins content, effective moisture diffusivity, drying rates, and energy efficiency. The current findings indicate that infrared drying is a promising drying technology for GBS and has the potential to be applied on a commercial scale. Practical applicationGinkgo seeds (GBS) are utilized as functional food across Asia. In China, ginkgo trees' extensive cultivation has surpassed market requirements, as GBS production could reach 60,000 tons per year. Therefore, there is an urgent need to find new opportunities to take advantage of the availability and usage of GBS regardless of the season and overcome the situation that GBS usage only remains at incipient phases of home-cooked recipes. Drying is a common approach to preserve foods'.Nonetheless, there are some drawbacks to conventional drying method, such as low energy efficiency, lengthy process periods, and a decline in quality attributes.

Non‐thermal pretreatment affects Ginkgo biloba L. seed's product qualities, sensory, and physicochemical properties

“…The infrared drying conditions were according to the infrared parameters optimized in the previous study (Boateng et al, 2020). The GBS were dried to a moisture content of 6% wet basis required for storage (Boateng et al., 2021).…”

“…Compared to Ginkgo leaves, Ginkgo biloba seeds (GBS) have a long history of usage (described by Herbals in 1350 AD) as GBSs are customarily consumed as medicine and food (Wang & Zhang, 2019). The GBS is an indispensable part of culinary culture as a nutritious meal, and it may also be used to make functional beverages, canned foods, and fruit candies, and can be made into different delicacies or desserts like ginkgo‐stewed chicken and ginkgo‐laba porridge (Boateng et al., 2021). In the year 2020, the export turnover of GB from China reached $1,812,754, according to China's General Administration of Customs (Liu et al., 2021).…”

“…People are, therefore, likely to eat less or even refuse to eat GBS, and few studies have centered on the production of new products for ginkgo seed (Lim & Kim, 2018). As far as China is concerned, due to the extensive cultivation of GB trees, which has gone far beyond the market requirements, GBS production can reach 60,000 tons per year (Boateng et al., 2021). Thus, new ways of taking advantage of GBS, especially the ways to reduce its toxicity and to ensure its edible safety, are urgent to establish and break the situation that the use of GBS only remains at the early stage of cooked dishes and processing products (Boateng et al., 2021; Lim & Kim, 2018).…”

Osmotic, osmovacuum, sonication, and osmosonication pretreatment on the infrared drying of Ginkgo seed slices: Mass transfer, mathematical modeling, drying, and rehydration kinetics and energy consumption

“…The rehydration experiment was performed using a slightly altered method by Boateng and Yang (2021). A 3 g of dried GBS was immersed in 150 mL of distilled water (60°C).…”

“…Drying remains a suitable method for preserving ginkgo seeds (Boateng et al., 2021). Nevertheless, ginkgo seed drying is a time and energy‐intensive procedure and had a varying effect on product qualities (Boateng & Yang, 2020; Boateng et al., 2020).…”