Optimized Conditions for the Extraction of Phenolic Compounds from Aeginetia indica L. and Its Potential Biological Applications.

Aeginetia indica L., a parasitic root in the Orobanchaceae family, is used as a food colorant in traditional Thai desserts. However, scant information is available on its food applications as well as medicinal properties, while overharvesting by the local people has severely depleted wild plant populations. This research, thus, aimed to extract optimized total phenolic content (TPC) in varying extraction conditions using response surface methodology (RSM) and the Box-Behnken design (BBD). Results indicated that an extraction temperature of 90 °C, 80% (v/v) aqueous ethanol, and 0.5% (w/v) solid-to-liquid ratio yielded the highest TPC at 129.39 mg gallic acid equivalent (GAE)/g dry weight (DW). Liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) identified the predominant phenolics as apigenin (109.06 mg/100 g extract) and luteolin (35.32 mg/100 g extract) with trace amounts of naringenin and rutin. Under the optimal extraction condition, the plant extract exhibited antioxidant activities of 5620.58 and 641.52 µmol Trolox equivalent (TE)/g DW determined by oxygen radical absorbance capacity (ORAC) and ferric ion reducing antioxidant power (FRAP) assay, while the scavenging capacity of total radicals at 50% (SC50) was determined to be 135.50 µg/mL using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. The plant extract also exhibited inhibitory activities against the key enzymes relevant to type II diabetes, obesity, and Alzheimer's disease, suggesting the potential for medicinal applications.

Nutritional Compositions, Phenolic Contents and Antioxidant Activities of Rainfed Rice Grown in Different Degrees of Soil Salinity.

Rice (Oryza sativa) is a staple food crop for over half of the world's population. However, drought as a result of climate change has led to increased soil salinity, thereby reducing agricultural potential, especially rice nutritional compositions and biochemical properties. Nevertheless, soil management by using suitable fertilizers might be able to improve rice quality even though these rice samples were grown in soil with a high degree of salinity. This study investigated nutritional compositions, phenolic contents, and antioxidant activities of twenty-five rainfed rice samples in Khao Dawk Mali 105 (KDML105) and Rice Department 15 (RD15) varieties grown in soil with different degrees of salinity. The soil, however, had been improved by the usage of fertilizer at the tillering and booting stages. Results indicated that all rice samples exhibited similar nutrients, total phenolic contents (TPCs), and antioxidant potentials, suggesting that appropriate fertilizer could improve rice qualities. Principle Component Analysis (PCA) and Pearson correlation results suggested that regardless of rice varieties, organic matter (OM) and soil potassium (Ks) showed a very strong positive correlation with protein and minerals (Ca, Na, K, and Fe), while opposite results were observed with soil pH. Moderate to very weak correlations were also observed between soil parameters and TPCs, as well as between soil parameters and antioxidant activities. The received information will be useful for the future development of appropriate fertilizer usage in salt-tolerant rice with particular nutritional quality.

Nutrients, Phytochemicals and In Vitro Disease Prevention of Nephelium hypoleucum Kurz Fruit.

Nephelium hypoleucum Kurz is an evergreen tree in the Sapindaceae family, mostly found in the forests of some Southeast Asia countries, especially Thailand. The lack of biological information regarding this tree has led to inappropriate agricultural management, conservation and utilization. Thus, this study aims to examine the nutritional composition, organic acid and phenolic profiles and in vitro health properties through several key enzyme inhibitions against some civilization diseases including Alzheimer's disease (ß-secretase (BACE-1), butyrylcholinesterase (BChE) and acetylcholinesterase (AChE)), obesity (lipase), hypertension (angiotensin-converting enzyme (ACE)) and diabetes (dipeptidyl peptidase-IV (DPP-IV), α-amylase and α-glucosidase) on the aril (flesh) part of N. hypoleucum Kurz fruit. The remaining fruit parts including the pericarp (peel) and seed were also assessed as sources of potential phenolics as well as key enzyme inhibitors. As results, carbohydrate (17.18 g) was found to be a major source of energy (74.80 kcal) in the aril (100 g fresh weight), with trace amounts of protein (0.78 g) and fat (0.32 g). The fruit aril also contained high insoluble dietary fiber (5.02 g) and vitamin C (11.56 mg), while potassium (215.82 mg) was detected as the major mineral. Organic acid profile indicated that the aril was rich in citric acid, while the phenolic profile suggested predominant quercetin and kaempferol. Interestingly, high gallic acid contents were detected in both pericarp and seed, with the latter 3.2-fold higher than the former. The seed also possessed the highest total phenolic content (TPC, 149.45 mg gallic acid equivalent/g dry weight), while total anthocyanin content (TAC, 0.21 mg cyanidin-3-O-glucoside equivalent/g dry weight) was only detected in pericarp. High TPC also led to high enzyme inhibitory activities in seed including BACE-1, AChE, BChE, ACE, DPP-IV and α-glucosidase. Interestingly, aril with the highest α-amylase inhibition suggested strong inhibitory distribution, predominantly from quercetin and kaempferol. Lipase inhibitory activities were only detected in the aril and pericarp, suggesting the biological function of these two phenolics and possibly anthocyanins.

Optimization of Enzyme-Assisted Mechanical Extraction Process of Hodgsonia heteroclita Oilseeds and Physical, Chemical, and Nutritional Properties of the Oils.

Hodgsonia heteroclita subsp. Indochinensis W.J.de Wlide & Duyfjes (or Making in Thai) is a neglected and underutilized crop (NUC) with high fat containing nuts. In this study, the enzyme-assisted mechanical extraction of H. heteroclita seed oil was investigated using response surface methodology (RSM) to predict the optimal fat extraction conditions. The most efficient enzyme used in the experiment was a mixture of Flavourzyme® and Viscozyme® (1:1, w/w). The predicted maximum oil yield was 46.44%, using the following extraction conditions: 2.98% (w/w) enzyme loading, 48 °C incubation temperature and 76 min of incubation time. H. heteroclita seed oil obtained from heat and enzymatic pretreatments exhibited the highest lightness and viscosity. The chemical properties of this seed oil, including water and volatile compounds (≤0.2% w/w), acid value (≤4.0 mg KOH/g), peroxide value (≤15 mEq of active oxygen/kg) and soap content (≤0.005% w/w), were within the acceptable levels specified by the Codex Alimentarius (2019). H. heteroclita seed oil obtained from heat and enzymatic pretreatments contained the highest content of δ-tocopherol (88.29 mg/100 g) and omega-6 fatty acids (48.19 g/100 g). This study is the first to report on the enzyme-assisted mechanical extraction of H. heteroclita oilseeds as a promising plant material for vegetable oil production.

Phenolic Profiles and Bioactivities of Ten Original Lineage Beans in Thailand.

Legumes and pulses are important food components with various phytochemicals and health benefits. However, the health-related bioactivities of some underutilized species remain uninvestigated. To breed a new bean lineage with particular health-related properties, this study investigated phenolics (specifically, isoflavones) and the in vitro inhibitory activities of the enzyme relevant to some non-communicable diseases in underutilized cultivars of Phaseolus lunatus (lima beans), compared to the commonly consumed P. vulgaris (red kidney bean) and beans in the Glycine and Vigna genera. The results indicated that soybeans in the Glycine genus contained the highest isoflavone contents, especially glycitein (1825-2633 mg/100 g bean) and daidzein (1153-6471 mg/100 g bean), leading to potentially higher enzyme inhibitory activities (25-26% inhibition against α-amylase, 54-60% inhibition against α-glucosidase, 42-46% inhibition against dipeptidyl peptidase IV, 12-19% inhibition against acetylcholinesterase and 20-23% inhibition against butyrylcholinesterase) than those from other genera. Interestingly, lima beans with low isoflavone content (up to 2 mg/100 g bean) still possessed high inhibitory activities against lipase (12-21% inhibition) and ß-secretase (50-58% inhibition), suggesting that bioactive compounds other than the isoflavones might be responsible for these activities. Isoflavone contents and enzyme inhibitory activities in Vigna beans were diverse, depending on the particular cultivars. The information gained from this study can be used for further investigation of bioactive components and in-depth health properties, as well as for future breeding of a new lineage of bean with specific health potentials.

Nutritional Compositions, Phenolic Contents, and Antioxidant Potentials of Ten Original Lineage Beans in Thailand.

Legumes and pulses are nutrient-dense foods providing a good source of protein, complex carbohydrates, fiber, vitamins, minerals, and bioactive compounds. To breed a new lineage of beans with specific nutritional and health beneficial purposes, more information on original lineage beans must be obtained. However, data concerning the nutritive compositions, total phenolic contents (TPCs), and health benefits regarding the antioxidant potentials of some original lineage beans in Thailand remain scarce, causing difficulty in decisional selection to breed a new lineage. Thus, this study aimed to examine the nutritional values (proximate compositions, vitamins, and minerals), TPCs, and antioxidant activities of ten original lineage bean cultivars in Glycine, Phaseolus, and Vigna genera from Genebank, Department of Agriculture (DOA), Thailand. The results indicated that beans in the Glycine genus potentially provided higher energy, protein, fat, and calcium contents than other genera, while the Phaseolus genus tended to provide higher carbohydrate and dietary fiber. Specifically, lima bean cultivar '38' exhibited high vitamin B1, and red kidney bean cultivar '112' exhibited high potassium content. Beans in the Vigna genus exhibited high TPCs and antioxidant activities. However, their nutritional compositions were markedly varied. The results of this work could support bean consumption as a feasible alternative diet and be used as a reference for future bean breeding (within the same genera) of a new lineage with particular nutritional requirements and health potentials.

Partial Substitution of Glucose with Xylitol Prolongs Survival and Suppresses Cell Proliferation and Glycolysis of Mice Bearing Orthotopic Xenograft of Oral Cancer.

Many types of cancer have metabolic alterations with increased glycolysis. Identification of alternative sweeteners that do not fuel cancer is a novel approach to cancer control. The present study aimed to investigate the effects of xylitol on tumor growth and survival of mice bearing orthotopic xenograft of tongue cancers. The results showed that partial substitution of glucose with xylitol (glucose 0.35 g plus xylitol 2.06 g/kg body weight) non-significantly reduced tumor volume, and significantly prolonged the median survival time from 19 days in the control to 30.5 days in the xylitol group. Immunohistochemical data of the tongue tissue shows significantly lower intense-to-mild staining ratios of the proliferation marker Ki-67 in the xylitol than those of the control group (p = 0.04). Furthermore, the xylitol substitution significantly reduced the expression of the rate-limiting glycolytic enzyme, phosphofructokinase-1 (PFK-1) (p = 0.03), and showed a non-significant inhibition of PFK activity. In summary, partial substitution of glucose with xylitol at the equivalent dose to human household use of 10 g/day slows down tumor proliferation and prolongs survival of mice bearing an orthotopic oral cancer xenograft, possibly through glycolytic inhibition, with minimal adverse events. The insight warrants clinical studies to confirm xylitol as a candidate sweetener in food products for cancer survivors.

Impact of Drying Processes on Phenolics and In Vitro Health-Related Activities of Indigenous Plants in Thailand.

Thailand has vast areas of tropical forests with many indigenous plants, but limited information is available on their phytochemical profile and in vitro inhibitions of enzymatic and nonenzymatic reactions. This study investigated phenolic profiles using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS), antioxidant activities, and in vitro inhibitory activities of 10 indigenous plants on key enzymes related to obesity (lipase), diabetes (α-amylase and α-glucosidase), and Alzheimer's disease (cholinesterases and ß-secretase). The nonenzymatic anti-glycation reaction was also investigated. The 10 indigenous plants were Albizia lebbeck (L.) Benth, Alpinia malaccensis (Burm.) Roscoe, Careya arborea Roxb., Diplazium esculentum (Retz.) Swartz, Kaempferia roscoeana Wall., Millettia brandisiana Kurz., Momordica charantia, Phyllanthusemblica L., Zingiber cassumunar Roxb, and Zingiber citriodorum J. Mood & T. Theleide. Preparations were made by either freeze-drying or oven-drying processes. Results suggested that the drying processes had a minor impact on in vitro inhibitions of enzymatic and nonenzymatic reactions (<4-fold difference). P. emblica was the most potent antioxidant provider with high anti-glycation activity (>80% inhibition using the extract concentration of ≤6 mg/mL), while D. esculentum effectively inhibited ß-secretase activity (>80% inhibition using the extract concentration of 10 mg/mL). C. arborea exhibited the highest inhibitory activities against lipase (47-51% inhibition using the extract concentration of 1 mg/mL) and cholinesterases (>60% inhibition using the extract concentration of 2 mg/mL), while Mi. brandisiana dominantly provided α-amylase and α-glucosidase inhibitors (>80% inhibition using the extract concentration of ≤2 mg/mL). Information obtained from this research may support usage of the oven-drying method due to its lower cost and easier preparation step for these studied plant species and plant parts. Furthermore, the information on in vitro inhibitions of enzymatic and nonenzymatic reactions could be used as fundamental knowledge for further investigations into other biological activities such as cell culture or in vivo experiments of these health-beneficial plants.

Influence of Plant Origins and Seasonal Variations on Nutritive Values, Phenolics and Antioxidant Activities of Adenia viridiflora Craib., an Endangered Species from Thailand.

Adenia viridiflora Craib. is an indigenous plant found in Thailand, Cambodia and Vietnam that has become threatened owing to lack of knowledge about its agricultural management. This plant is now rare in the wild and was registered in the Plant Genetic Conservation Project under the initiation of Her Royal Highness Princess Maha Chakri Sirindhorn (RSPG) to promote sustainable conservation and optimally beneficial utilization. A. viridiflora has a long history of utilization as a nutrient-rich source with medicinal properties but scientific evidence of the veracity of these claims is limited. Here, the nutritional compositions, phenolic contents and antioxidant activities of different plant parts (young shoots and old leaves) of A. viridiflora were investigated using plants collected from four areas of Thailand as Kamphaeng Phet (KP), Muang Nakhon Ratchasima (MN), Pakchong Nakhon Ratchasima (PN) and Uthai Thani (UT) at different harvesting periods (March-April, May-June and July-August). Results indicated that young shoots provided higher energy, protein, fat, dietary fiber, phosphorus, sodium, and zinc than old leaves. By contrast, nutrients such as total sugar, vitamin C, carotenoids, potassium, calcium, magnesium, and iron contents were higher in old leaves that also exhibited higher phenolic contents and most antioxidant activities than young shoots. Generally, most nutrients, phenolic contents, and antioxidant activities exhibited no clear trend among different plant origins. The harvesting period of July-August provided a suitable climate for biosynthesis of most nutrients, while high phenolics were mainly found in samples harvested in March-April. No clear trend was observed in the prevalence of antioxidant activities that varied according to assay techniques.

A Comparison of the Nutritional and Biochemical Quality of Date Palm Fruits Obtained Using Different Planting Techniques.

Date palm fruit (Phoenix dactylifera L.) is commonly consumed around the world and has recently become an economical crop in Eastern Thailand, especially the Barhi cultivar that can be consumed as fresh fruit. To maintain genetic qualities, date palm is populated through cell culture. This leads to high production costs, while access to this technique is limited. Increasing date palm population by simple seed planting is currently of interest as an alternative for local farmers. Nevertheless, information on nutritive values, bioactive compounds, and health-promoting bioactivities of seed originating from date palm fruit is unavailable. Effects of different planting origins (cell culture origin (CO) and seed origin (SO)) of date palm fruits at the Khalal stage of Barhi cultivar were investigated for nutritive values, bioactive compounds, and in vitro health-promoting properties via key enzyme inhibitions against obesity (lipase), diabetes (α-amylase, α-glucosidase, and dipeptidyl peptidase-IV), Alzheimer's disease (cholinesterases and ß-secretase), and hypertension (angiotensin-converting enzyme). Waste seeds as a by-product from date palm production were also examined regarding these properties to increase seed marketing opportunities for future food applications and other health-related products. CO and SO exhibited insignificant differences in energy, fat, and carbohydrate contents. SO had higher protein, dietary fiber, vitamin A, vitamin E, and calcium contents than CO, while CO contained higher contents of fructose, glucose and maltose. Higher phenolic contents in SO led to greater enzyme inhibitory activities than CO. Interestingly, seeds of date palm fruits mostly contained higher nutritive values than the flesh. No carotenoids were detected in seeds but higher phenolic contents resulted in greater enzyme inhibitory activities than recorded for fruit flesh. Results suggest that appropriate planting of date palm can support the development of novel date palm fruit products, leading to expansion of economic opportunities and investment in date palm fruit agriculture.

The Effect of Steaming and Fermentation on Nutritive Values, Antioxidant Activities, and Inhibitory Properties of Tea Leaves.

Fermented tea (Cha-miang in Thai) is a local product made by traditional food preservation processes in Northern Thailand that involve steaming fresh tea leaves followed by fermenting in the dark. Information on changes in nutritive values, bioactive compounds, antioxidant activities, and health properties that occur during the steaming and fermenting processes of tea leaves is, however, limited. Changes in nutritive values, phenolics, antioxidant activities, and in vitro health properties through inhibition of key enzymes that control obesity (lipase), diabetes (α-amylase and α-glucosidase), hypertension (angiotensin-converting enzyme (ACE)), and Alzheimer's disease (cholinesterases (ChEs) and ß-secretase (BACE-1)) of fermented tea were compared to the corresponding fresh and steamed tea leaves. Results showed that energy, carbohydrate, and vitamin B1 increased after steaming, while most nutrients including protein, dietary fiber, vitamins (B2, B3, and C), and minerals (Na, K, Ca, Mg, Fe, and Zn) decreased after the steaming process. After fermentation, energy, fat, sodium, potassium, and iron contents increased, while calcium and vitamins (B1, B2, B3, and C) decreased compared to steamed tea leaves. However, the contents of vitamin B1 and iron were insignificantly different between fresh and fermented tea leaves. Five flavonoids (quercetin, kaempferol, cyanidin, myricetin, and apigenin) and three phenolic acids (gallic acid, caffeic acid, and p-coumaric acid) were identified in the tea samples. Total phenolic content (TPC) and antioxidant activities increased significantly after steaming and fermentation, suggesting structural changes in bioactive compounds during these processes. Steamed tea exhibited high inhibition against lipase, α-amylase, and α-glucosidase, while fermented tea possessed high anti-ChE and anti-ACE activities. Fresh tea exhibited high BACE-1 inhibitory activity. Results suggest that tea preparations (steaming and fermentation) play a significant role in the amounts of nutrients and bioactive compounds, which, in turn, affect the in vitro health properties. Knowledge gained from this research will support future investigations on in vivo health properties of fermented tea, as well as promote future food development of fermented tea as a healthy food.

Nutritional composition of conserved Kadsura spp. plants in Northern Thailand.

The genus Kadsura comprises woody vine plants belonging to the family Schisandraceae. Species are found mostly in Northern Thailand and widely consumed by the local population. Occurrences of these wild fruits are rare as they only grow naturally in forest areas. Nutritive values of Kadsura spp. remain unclear, leading to improper management for food applications. Nutritional composition of Kadsura spp. was evaluated to promote sustainable conservation. Nutritive values in different fruits parts (exocarp, mesocarp, seed and core) of two Kadsura species as Kadsura coccinea (Lem.) A.C. Sm. and Kadsura heteroclita (Roxb.) Craib, from Chiang Rai Province, Thailand were assessed. When comparing nutritional contents based on per 100 g dry weight, results suggested that K. coccinea exhibited higher carbohydrate (1-2 times), sugar (1-2 times) and vitamin C (3-4 times) contents than K. heteroclita, while the latter possessed higher fat (1-2 times), protein (1.6-1.9 times), and dietary fiber (1.5-1.8 times) contents. Considering each fruit part, the mesocarp (the only edible fruit part) and exocarp of both species provided high dietary fiber (11.6-20.9% recommended dietary fiber) and vitamin C (as high as 73% recommended per day) but were low in energy (30-40 kcal/100 g fresh weight), protein (0.6-1.2% recommended per day), fat (0.5-1.8% recommended per day) and sugar (2.4-5.4% recommended per day). Interestingly, seed contained higher energy (1-2 times), protein (2-3 times) and fat (4-50 times) than the other fruit parts. Results support the potential consumption of Kadsura spp. as a healthy fruit that can be used for future food applications. Seed and exocarp from Kadsura spp. also showed potential for new product development.