Exploring Fatty Acid Composition and Nutritional Profiles in Tea Seed Oils from Different Varieties

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Tea seed oil, extracted from the seeds of the tea plant (Camellia sinensis), is gaining recognition as a highly nutritious and versatile edible oil.

A groundbreaking 2025 study published in LWT – Food Science and Technology offers the most detailed analysis yet of its fatty acid composition, antioxidant properties, and genetic mechanisms.

Introduction: The Rising Importance of Tea Seed Oil

China, the world’s largest tea producer, cultivates tea across 51.49 million mu (approximately 3.43 million hectares), producing 3.34 million tons of dry tea annually.

Despite this massive output, tea seeds—packed with unsaturated fats, proteins, and antioxidants—are often discarded. In 2009, China’s Ministry of Health recognized tea seed oil as a novel food resource, sparking interest in its potential to rival olive oil.

The recent study analyzed 48 tea varieties from Sichuan, China, alongside Camellia oleifera (YC, a traditional oilseed crop), to explore its nutritional value and genetic foundations.

Below, we delve into the study’s key discoveries, from fatty acid profiles to the genes that make certain tea varieties oil-rich.

Variability in Oil Content Across Tea Seed Varieties

The study revealed significant differences in oil content among tea seeds.

On average, the oil content was 25.17%, but this varied widely—from 17.91% in the Zhenong No.113 variety to 32.97% in Huangjingui.

Interestingly, small-leaf tea varieties generally contained more oil than large-leaf types, aligning with historical data showing Chinese tea seeds typically hold 24–30% oil.

Surprisingly, physical traits like seed size or weight showed no direct link to oil content. For instance, the Chuanmu No.5 (CMS) variety, with medium-sized seeds, had the highest 100-grain weight (386.1 g), but this didn’t correlate with oil richness.

Instead, genetic factors played a larger role, as seen in later sections.

Fatty Acid Composition: A Closer Look at Nutritional Benefits

Using advanced techniques like Gas Chromatography-Mass Spectrometry (GC-MS), researchers identified 31 fatty acids in tea seed oils. Three key components stood out:

Palmitic acid (C16:0): A saturated fat making up 14.11–16.90% of total fats. While saturated fats are often linked to higher cholesterol, their moderate presence here balances the oil’s stability and nutritional profile.

Oleic acid (C18:1n9c): A heart-healthy monounsaturated fat constituting 35.75–48.83% of the oil. Oleic acid is known to reduce LDL (“bad”) cholesterol and is a major component of olive oil.

Linoleic acid (C18:2n6c): An essential polyunsaturated fat (not produced by the human body) accounting for 25.41–36.39%. Linoleic acid supports brain function, skin health, and hormone production.

Compared to Camellia oleifera oil, tea seed oil contains 42.98–45.76% polyunsaturated fatty acids (PUFAs)—nearly 1.5 times higher than YC oil.

PUFAs, with their multiple double bonds, are vital for cell structure and reducing inflammation. Additionally, tea seed oil lacks harmful fats like erucic acid and behenic acid, which are hard to digest and found in some vegetable oils.

Unique compounds like trans-oleic acid (C18:1n9t) and cis-13,16-docosadienoic acid (C22:2) were also detected, setting it apart from other oils.

Antioxidants: The Hidden Health Boosters in Tea Seed Oil

Tea seed oil isn’t just rich in fats—it’s also loaded with antioxidants, which protect cells from damage caused by free radicals (unstable molecules linked to aging and diseases). The study highlighted three major antioxidants:

Tocopherols (Vitamin E):

α-tocopherol (0.24–0.64 mg/g): The most active form of Vitamin E, known for shielding cell membranes from oxidative damage. δ-tocopherol (0.19–0.42 mg/g): Contributes to the oil’s shelf life by preventing rancidity.

Tea seed oil contains 55–211% more tocopherols than YC oil, surpassing even coconut oil (0.024–0.664 mg/g).

Catechins:

Gallocatechin gallate (GCG): A potent antioxidant (0.43–0.56 mg/g) previously unreported in YC oil, shown to inhibit tumor growth.

Epicatechin (EC): Improves blood flow and heart health.
Total catechin content ranged from 1.11–2.10 mg/g, with Zixian (ZX) and Huangjingui (HJG) varieties leading the pack.

Caffeine:

Found in small amounts (0.74–5.13 mg/g), caffeine adds a unique edge to tea seed oil. While absent in most cooking oils, it may enhance metabolic rate and alertness.

Quality Metrics: Why Tea Seed Oil Stands Out

The study evaluated tea seed oil using four key industrial parameters: Iodine value (55.73–75.02 g/100g): Measures unsaturation. Higher values indicate more double bonds, which are healthier but require careful storage to avoid oxidation.

Saponification value (165.07–203.91 mg/g): Reflects fatty acid chain length. Shorter chains mean purer oil. Acid value (0.29–0.99 mg/g): Indicates freshness. Lower values mean fewer free fatty acids and reduced rancidity risk.

Peroxide value (0.7–3.29 mmol/kg): Measures oxidation. Lower values signal greater stability.

When compared to YC oil, tea seed oil excelled with 30–75% higher iodine values and lower acid/peroxide levels, making it nutritionally superior and longer-lasting.

Genetic Secrets: How Tea Plants Produce High-Quality Oil

To uncover why some tea varieties produce more oil, researchers compared Chuanmu No.3 (CM3) (high oil: 32.97%) and Chuanmu No.4 (CM4) (low oil: 17.91%) using RNA sequencing.

They identified 5,811 differentially expressed genes (DEGs), with 2,660 genes more active in high-oil varieties. Key findings included:

Fatty Acid Desaturase (CSS013596): This gene adds double bonds to fatty acids, converting saturated fats to unsaturated ones. CM3 had 2.4 times more cis-9-palmitoleic acid (C16:1) than CM4, linked to this gene’s overexpression.

Fatty Acid Elongase (CSS031352): Extends fatty acid chains, influencing texture. CM3’s behenic acid (C22:0) levels were twice as high as CM4’s due to this gene’s activity.

Plant Hormone Pathways: Auxins (growth hormones) and gibberellins (stem elongation hormones) likely triggered oil accumulation in high-yield varieties.

These genetic insights pave the way for breeding tea plants optimized for both leaf and seed production.

Tea Seed Oil vs. Camellia Oleifera Oil: A Nutritional Showdown

When stacked against Camellia oleifera (YC), tea seed oil shines in several areas: Polyunsaturated Fats (PUFAs): Tea seed oil contains 42.98–45.76% PUFAs vs. YC’s 30.36%, offering better support for heart and brain health.

Antioxidants: With 55–211% more tocopherols and unique catechins like GCG, tea seed oil outperforms YC in combating oxidative stress.

Digestibility: Free of hard-to-digest fats like erucic acid, it’s gentler on the stomach.

However, YC oil has higher oleic acid levels (54.5–80.2%), similar to olive oil. This makes YC better for high-heat cooking, while tea seed oil offers a more balanced nutritional profile.

Health, Agricultural, and Industrial Implications

Health Benefits:

Tea seed oil’s high PUFA content reduces LDL cholesterol and inflammation, while antioxidants like catechins combat aging and diseases. Its unique caffeine content may also boost metabolism.

Agricultural Advancements:

Farmers can now breed dual-purpose tea plants—harvesting leaves for tea and seeds for oil. Molecular tools like gene editing could enhance oil yield using key genes (e.g., CSS013596).

Industrial Uses:

Culinary: With a high smoke point (~220°C), it’s ideal for frying and baking. Cosmetics: Antioxidants like GCG make it valuable in anti-aging creams. Biofuels: Its high saponification value hints at biodiesel potential.

Challenges and Future Opportunities

Despite its promise, tea seed oil faces hurdles:

Standardization: Oil content varies widely (17.91–32.97%), requiring strict quality control. Oxidation: While tocopherols extend shelf life, blending with stable oils (e.g., olive oil) could improve durability.

Consumer Awareness: Many remain unaware of its benefits. Marketing it as a “super oil” could drive adoption.

Future research should focus on:

Clinical Trials: Testing cholesterol-lowering and anti-inflammatory effects in humans. Sustainable Practices: Optimizing cold-pressing methods to preserve heat-sensitive antioxidants.

Conclusion: The Future of Tea Seed Oil

This study transforms tea seed oil from an overlooked byproduct into a nutritional powerhouse.

With over 80% unsaturated fats, unique antioxidants, and a genetic blueprint for high yield, it offers a healthier, sustainable alternative to traditional oils.

By leveraging key genes like CSS013596, farmers can cultivate tea plants that maximize both leaf and seed value.

As research progresses, tea seed oil may soon join olive and avocado oils as a kitchen essential—proving that sometimes, the most extraordinary innovations come from reimagining the ordinary.