Page 55 - FoodFocusThailand No.221 August 2024

STRATEGIC R & D

enhancing fatty acid oxidation. However, the browning decaffeinated green tea extract can increase the conversion
effect of proanthocyanidin extract from grape seeds of white adipose tissue into brown-like adipose tissue by the
requires further study. Apart from numerous browning effect mechanism, thereby increasing cellular
proanthocyanidins research, resveratrol extract, another energy expenditure. Additionally, studies on gene expression,
polyphenol from grape seeds, has been extensively studied. the activation of the AMPK pathway, and the effects of oolong
Reports indicate that resveratrol can increase triglyceride tea and Pu-erh tea have been explored. Studies on oolong
breakdown into free fatty acids and glycerol, boost fatty tea and Pu-erh tea extracts have also found that these
acid oxidation, and enhance mitochondrial biogenesis, extracts can convert white adipose tissue into brown-like
thereby promoting energy expenditure. Nevertheless, adipose tissue and stimulate biological pathways such as
human studies on resveratrol consumption still lack AMPK.
sufficient evidence to conclusively determine its In addition to promoting the conversion of white adipose
effectiveness in managing obesity. tissue to brown-like adipose tissue, tea extracts also increase
Citrus extracts such as oranges, lemons, and fat utilization through oxidation processes. The oxidation
grapefruits have been reported to boost energy expenditure. processes are regulated by several enzymes such as
The active compounds in citrus extracts with these Hormone Sensitive Lipase (HSL) and Adipocyte Triglyceride
properties are citrus flavonoids, which include a variety of Lipase (ATGL). It has been reported that catechins from
essential substances such as hesperidin, hesperetin, green tea can increase the expression of the gene
naringenin, naringin, tangeretin, nobiletin, quercetin, and Proliferator-activated Receptor Gamme (PPARδ), which
kaempferol as well as citrus carotenoids and terpenes, like controls fat oxidation processes, along with other related
β-cryptoxanthin and dietary fibers. Studies on the efficacy genes, indicating an increase in fat oxidation processes.
of citrus extracts in humans, along with systematic reviews However, tea contains not only flavonoids, which are crucial
and meta-analyses, conclude that consuming citrus plants active compounds, but also caffeine, which stimulates energy
and their extracts can reduce body mass index (BMI), waist expenditure. Additionally, tea extracts help inhibit fat
circumference, hip circumference, and body weight, synthesis and accumulation as well.
increasing effectiveness according to the concentration. From the examples of plant extracts mentioned above,
Citrus extracts enhance energy expenditure by stimulating it can be concluded that certain plants can be used as raw
β-3 cell receptors and increasing mitochondrial synthesis, materials to extract bioactive compounds for use as functional
as well as converting white adipose tissue to brown adipose food ingredients. The processes that enable these extracts
tissue, which further increases energy and fat metabolism. to aid in energy expenditure often involve stimulating the
The final group of extracts to discuss are tea extracts. AMPK pathway and oxidation processes and increasing the
Tea can be categorized based on the fermentation and conversion of white adipose tissue to brown-like adipose
processing processes into white, yellow, green, oolong, tissue, leading to increased fat oxidation. Nonetheless, some
black, and dark tea. Tea contains a variety of active plant extracts still require further human studies to
compounds, including polyphenols, polysaccharides, amino substantiate their efficacy, necessitating additional clinical
acids, and alkaloids. Tea leaves have been reported to studies.
have various biological properties, such as antioxidant,
anti-inflammatory, and immune-modulating effects, as well
as reducing the risk of diabetes, certain cancers, and
obesity. Consumption data shows that drinking tea has More Information Service Info C007
minimal adverse effects on the body and is safe when
consumed in common amounts. Human studies have found
that tea consumption can reduce weight and body เอกสารอ้างอิง / References
measurements due to increased energy expenditure, - Yuliana, N. D., Korthout, H., Wijaya, C. H., Kim, H. K., & Verpoorte,
reduced digestion and nutrient absorption, increased fat R. (2013). Plant-Derived Food Ingredients for Stimulation of
breakdown, reduced fat synthesis, decreased fat Energy Expenditure. Critical Reviews in Food Science and
accumulation in adipocytes, improved nervous system Nutrition, 54(3), 373–388. https://doi.org/10.1080/10408398.201
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enhancing properties of tea extracts have been widely - Miao Liu, Peng Yun, Ying Hu, Jiao Yang, Rim Bahadur
studied at the cellular level, in experimental animals, and Khadka, Xiaochun Peng; Effects of Grape Seed Proanthocyanidin
in clinical studies. Animal studies have shown that Extract on Obesity. Obes Facts 7 May 2020; 13 (2): 279–291.
- Fernández-Quintela, A., Milton-Laskibar, I., González, M. and
Portillo, M.P. (2017), Antiobesity effects of resveratrol: which
tissues are involved?. Ann. N.Y. Acad. Sci., 1403: 118-131.
https://doi.org/10.1111/nyas.13413
- Merve Nur Aslan, Betül Sukan-Karaçagıl, Nilüfer Acar-Tek, Roles
of citrus fruits on energy expenditure, body weight management,
and metabolic biomarkers: a comprehensive review, Nutrition
Reviews, 2023;, nuad116, https://doi.org/10.1093/nutrit/nuad116
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Y., … Li, H. B. (2021). Effects and mechanisms of tea on
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