Effects of roasting conditions on physicochemical properties and antioxidant activities in Ginkgo biloba seeds

2021

J Sci Food Agric

BACKGROUND: Ginkgo biloba seeds are used as a functional food across Asia. However, the presence of toxic compounds has limited their application. In this study, freeze drying, infrared drying, hot-air drying and pulsed-vacuum drying were used to dry G. biloba seeds. A comprehensive analysis was performed on their product quality, antioxidant activities, bioactive and toxic components.RESULTS: Results showed that the drying methods had a significant influence on product quality with freeze drying being superior due to the minimal microstructural damage, followed by infrared drying and pulsed-vacuum drying. Infrared-dried product possessed the strongest antioxidant activities and higher bioactive compound content than hot-air-dried and pulsed-vacuumdried product. Toxic compounds in fresh G. biloba seeds (ginkgotoxin, ginkgolic acid and cyanide) were reduced markedly by drying. Ginkgotoxin was reduced fourfold, and the contents of acrylamide, ginkgolic acid and cyanide in dried G. biloba seeds were reduced to the scope of safety. Amongst the four drying methods, infrared drying had the shortest drying time, and its product showed higher quality and bioactive compound content, and stronger antioxidant activities.CONCLUSIONS: These findings will offer salient information for selecting a drying method during the processing of ginkgo seeds. Infrared drying could be considered as a multiple-effect drying method in the processing of ginkgo seeds.

Section: Resultsmentioning

confidence: 91%

Section: Antioxidant Activity Assaysmentioning

confidence: 99%

Section: Antioxidant Activities Of Gbsmentioning

confidence: 99%

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Effect of different drying methods on product quality, bioactive and toxic components of Ginkgo biloba L. seed

2021

J Sci Food Agric

“…A similar result was reported by Hamrouni‐Sellami et al (2013), in which they had an increase in phenolic contents after drying with various methods. The increase in NTPC after drying could be explained that, during drying, cellular constituents' catabolize, leading to the acceleration of phenolic compounds from the food matrix (Boateng & Yang, 2020; Lim & Kim, 2018; Valadez‐Carmona et al, 2017). This findings agreed with Valadez‐Carmona et al (2017), as they observed that a greater quantity of phenolic content is preserved by temperatures below 110°C and a longer treatment time.…”

Section: Resultsmentioning

confidence: 99%

“…This might be explained that, as tannic compounds are mainly present in bound form and are connected to vegetables and fruits cell walls. Therefore, non‐thermal or thermal dehydration may lead to the liberation of such bound phenolic by breaking the cells' structures (Dzah et al, 2020; Hamrouni‐Sellami et al, 2013; Lim & Kim, 2018), thus causing more tannins in the ginkgo seeds to be extracted. The infrared‐dried GBS had the highest tannins (CT and hydrolyzable tannins, HT), and it can be explained by the points above.…”

Section: Resultsmentioning

confidence: 99%

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

Soetanto

J Food Process Engineering

et al. 2021

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.

Effects of processing methods on quality, antioxidant capacity, and cytotoxicity of Ginkgo biloba leaf tea product

et al. 2023

J Sci Food Agric

BACKGROUND: Ginkgo biloba leaves contain beneficial flavonoids, bilobalide (BB), and ginkgolides. However, the toxic ginkgolic acid (GA) limit its application. In this study, various traditional processing methods were used to prepare G. biloba leaf tea (GBLT), including white tea, black tea, dark tea, green tea, and freeze-dried as control, followed by investigations of their effects on quality, antioxidant capacity, bioactive components, and cytotoxicity of the tea products.RESULTS: Results showed that different processing methods significantly impact the tea products' quality indexes and the principal component analysis (PCA) and hierarchical cluster analysis (HCA) corroborated it. White tea had the highest total sugar (TS) and GA content and the most potent cytotoxicity on HepG2 cells. However, TS and GA content and the cytotoxicity of GBLT markedly decreased during fermentation and fixation. Moreover, white tea possessed higher total phenolic content (TPC), total flavonoid content (TFC), and more vigorous antioxidant activities than green tea, black tea, and dark tea. Terpene trilactones value was stable, but different catechins contents fluctuated according to the manufacturing process of different GBLTs. Among the four GBLTs, dark tea combining fixation and fermentation had the lowest GA content and cytotoxicity, less bioactive components reduction, appropriate quality, and stronger flavor.CONCLUSION: These findings demonstrate that fixation and fermentation help reduce GAs during the manufacturing of GBLT. However, their ability to retain bioactive substances needs further optimization in future studies.