Quandong (Santalum acuminatum) is a member of the sandalwood family and is considered one of Australia’s most versatile native foods. Also called desertQuandong, sweetQuandong, native peach,¹wild peach, desert peach, Guwandhuna, Gutchu, Wanjanu, Mangata, Goorti, and Wadjal,² the Quandong trees are drought-tolerant and grow throughout Australia’s arid and semi-arid regions.

The Quandong fruit has a distinct flavour and can be peeled for use in pies, jams, and chutneys. The hard-shelled Quandong nuts can be eaten raw but are usually roasted. Among men of central Australia's Pitjantjara people, Quandongs were considered a suitable substitute for meat.²

Quandong is an antioxidant powerhouse

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are produced by various metabolic processes. Excessive production of ROS and RNS in the body ultimately causes oxidative stress, which is also the leading cause of many different pathological conditions⁴ including cognitive dysfunction and heart disease.

Antioxidants can minimise or neutralise the free radicals in the body as well as the detrimental effects of chronic inflammation in various organ systems. These powerful chemicals are naturally available in many plants, including Quandong. 

Scientific studies have demonstrated the beneficial effects of antioxidants on various body organ systems, including cardiovascular health, respiratory function, liver and kidney function, and eye health.

Like the Kakadu plum (Terminalia ferdinandiana), Quandong (Santalum acuminatum) has superior oxygen radical-scavenging capacity.⁶

Quandong has been found to have the highest oxygen radical scavenging capacity (ORAC assay) among eight commercially grown native Australian fruits that include Kakadu plum, lemon aspen, Australian desert lime, Davidson’s plum, Finger lime (green and pink), Riberry, and blueberry. Quandong is rich in hydroxycinnamic acids, flavonols, and anthocyanins, which could be primarily responsible for the high ORAC values.⁹

Table 1. Total phenolic content and antioxidant capacity of selected commercially grown native Australian fruits.

Fruit	Total phenolics (FC) (µmol GA E/g FW)	ORAC-H (µmol TEq/g FW)
Australian desert lime**	10.8 ± 0.4	44.9 ± 5.1
Kakadu plum**	159.6 ±1.2♦	315.4 ± 33.7♦
Lemon aspen	9.5 ± 0.3	131.5 ± 11.4
Davidson's plum	15.9 ± 1.3♦	83.1 ± 10.9♦
Finger lime (green)**	6.8 ± 0.4	45.9 ± 6.6
Finger lime (pink)**	9.2 ± 0.5	65.1 ± 12.8
Riberry	7.5 ± 0.7	49.9 ± 6.4
Quandong	50.4 ± 0.4	501.0 ± 64.1
Blueberry	26.5 ±0.6	76.9 ± 13.3

Source:Hydrophilic phytochemical composition and anti-oxidant capacity of commercially grown native Australian fruits 

Antioxidants in Quandong support cognitive function 

Oxidative damage is an important predisposing factor of cognitive dysfunction.
 

Antioxidants have been demonstrated to support cognitive function, such as slowing down mental decline in senior dogs and helping reduce the development of age-related changes in behaviour.

Rutin is one of the substances in Quandong that plays a key role in preventing cognitive dysfunction.Rutin, also known as vitamin P or rutoside, is a natural flavonoid with a wide range of biological activities, including important neuroprotective effects. 

Many scientific studies have demonstrated a number of pharmacological activities, including antioxidant, cytoprotective, vasoprotective, anticarcinogenic, neuroprotective, and cardioprotective activities.¹⁰ A 2012 study demonstrated the powerful actions of rutin on multiple pathogenic factors associated with the development of Alzheimer’s disease in humans.¹¹

Rutin contains quercetin and the disaccharide rutinose. Quercetin acts as an efficient radical inhibitor and is reported to improve spatial memory impairment in rats and decrease senile plaques in the brain of APP transgenic mice. Rutin has also been demonstrated to reduce cognitive effects and brain impairment in mice.¹¹ 

Cognitive dysfunction syndrome (CDS) is a common age-related disease in dogs that affects the brain, causing deterioration similar to Alzheimer's disease in humans. Both conditions are associated with gradual and degenerative age-related changes in the brain.¹²

Quandong is rich in polyphenols

Polyphenols are powerful antioxidants. These naturally occurring chemicals protect the body against oxidative stress in several ways.

Polyphenols are the main antioxidant compounds that can neutralize the free radicals in the body.⁴ Recent data support their beneficial effects, including antioxidant, anti-inflammatory, and anti-cancer activities.⁵

Nutritionists suggest that polyphenols-rich fruits and vegetables can inhibit or lower the risk of cardiovascular diseases, chronic inflammation, degenerative diseases, and various cancers in the human body.⁴

Quandong has a higher antioxidant capacity than blueberry, a fruit that is widely known for being rich in antioxidants.³ Like Davidson Plum, it’s high in the antioxidant anthocyanin, shown to have neuroprotective actions including suppression of neuroinflammation, delaying cognitive dysfunction and improving learning and memory.  

These are key reasons why Quandong, along with Davidson Plum, is an ingredient in our Senior health chew for dogs. It works with amino acids and herbs like boswellia and gingko, in a highly therapeutic, soft mini chew to help delay mental decline.

 

 

Table2. Measurement ofPhenolic contents in Australian native fruits.

Variables	TPC (mg GAE/g)	TFC (mg QE/g)	TCT (mg CE/g)	TMAC (mg C3G/g)
Kakadu Plum	74.84 ± 4.28 a	16.07 ± 0.74b	5.44 ± 1.76b	0.00 ± 0.00 d
Quandong Peach	42.85 ± 0.39b	20.63 ± 0.30 a	3.90 ± 0.93c	2.07 ± 0.20b
Davidson Plum	32.49 ± 0.79c	10.56 ± 0.13c	6.31 ± 1.75 a	2.80 ± 0.33 a
Muntries	23.04 ± 1.19 d	8.31 ± 2.04 d	2.14 ± 0.67 d	0.78 ± 0.09c

Source:Identification and characterization of anthocyanins and non-anthocyanin phenolics from Australian native fruits and their antioxidant, antidiabetic, and anti-Alzheimer potential

***TPC; total phenolic content, TFC; total flavonoid content, TCT; total condensed tannins, TMAC; total monomeric anthocyanin content

Other essential nutrients in Quandong

In addition to the outstanding antioxidant capacity, Quandong also contains high levels of folate and vitamin E. It is a good source of magnesium, zinc, and iron at levels higher than the blueberry.⁷

Table 3.Nutritional Composition Of Quandong

Total phenolic content	8.57 ± 0.61
α-tocopherol	1.165 ± 0.078
β-tocopherol	0.086±0.005
γ-tocopherol	0.038 ± 0.005
Vitamin E  (mg/100g FW)	1.289
Vitamin A (mg RAAE/100 g DW)	10**
Vitamin E (mg/100 g DW)	0.7–4.78**
Vitamin B (mg/100 g FW )	Thiamine 0.04**
Vitamin C  (mg/100 g FW )	0.2–20**
Folate  (µg/100g FW)	28.0±2.8
Iron (mg/100g DW)	16.6
Copper (mg/100g DW)	0.100
Manganese (mg/100g DW)	0.288
Zinc (mg/100g DW)	4.240
Calcium (mg/100g DW)	133.3
Magnesium (mg/100g DW)	217.9
Potassium (mg/100g DW)	3456.2
Phosphorus (mg/100g DW)	97
Selenium (mg/100g DW)	<0.001
Molybdenum (mg/100g DW)	0.0556
Nickel (mg/100g DW)	0.015
Cobalt (mg/100g DW)	0.002
Sodium (mg/100g DW)	306
Sulfur (mg/100g DW)	125
Malic Acid (mg/g FW)	19.1 ± 1.33
Oxalic Acid (mg/g FW)	0.40 ± 0.01

Sources:

*Australian Aboriginal Bushfoods: Their Nutritive Value

**Australian native fruits and vegetables: Chemical composition, nutritional profile, bioactivity and potential valorization by industries

Dr. Merliza Cabriles, DVM  

Dr. Merliza Cabriles is a Licensed Veterinarianand a University Professor with many years of experience in food animal and pet companion medicine. Her passion for writing and pet parent education and support are echoed in the articles she has written for various websites in the pet niche, including bestie’s! She enjoys cultivating positive relationships with her clients and dedicates her time to educating and supporting pet parents in providing the best care for their pets.In her spare time, she enjoys trekking and traveling.

List of References:

1. Britannica, The Editors of Encyclopaedia. "Quandong". Encyclopedia Britannica, 8 Nov. 2021, https://www.britannica.com/plant/Quandong. Accessed 17 March 2023 

2. Sibylla Hess-Buschmann. Quandong. Australian Native Food & Botanicals.

3. Karunrat Sakulnarmrat, George Srzednicki, Izabela Konczak. Composition and inhibitory activities towards digestive enzymes of polyphenolic-rich fractions of Davidson's plum and Quandong. LWT - Food Science and Technology Volume 57, Issue 1, June 2014, Pages 366-375.

4. Akhtar Ali, Jeremy J. Cottrell, Frank R. Dunshea. Identification and characterization of anthocyanins and non-anthocyanin phenolics from Australian native fruits and their antioxidant, antidiabetic, and anti-Alzheimer potential. Food Research International Volume 162, Part B, December 2022, 111951.

5. Adisakwattana S. Cinnamic Acid and Its Derivatives: Mechanisms for Prevention and Management of Diabetes and Its Complications. Nutrients. 2017 Feb 21;9(2):163. doi: 10.3390/nu9020163. PMID: 28230764; PMCID: PMC5331594. 

6. Izabela Konczak, Dimitrios Zabaras, Matthew Dunstan, Patricia Aguas. Antioxidant capacity and hydrophilic phytochemicals in commercially grown native Australian fruits. Food Chemistry Volume 123, Issue 4, 15 December 2010, Pages 1048-1054. 

7. Sun, Xy., Li, Lj., Dong, QX. et al. Rutin prevents tau pathology and neuroinflammation in a mouse model of Alzheimer’s disease. J Neuroinflammation 18, 131 (2021). https://doi.org/10.1186/s12974-021-02182-3

8. Australian Native Food Industry Ltd.Quandong (Santalum acuminatum). RURAL INDUSTRIES R&D CORPORATION industry overview. 

9. Izabela Konczak, Dimitrios Zabaras, Matthew Dunstan, Patricia Aguas. Hydrophilic phytochemical composition and anti-oxidant capacity of 2 commercially grown native Australian fruits. CSIRO Food and Nutritional Sciences, PO Box 52, North Ryde, NSW 1670, AUSTRALIA.

10. Aditya Ganeshpurkar Ajay K. Saluja. The Pharmacological Potential of Rutin. Saudi Pharmaceutical Journal Volume 25, Issue 2, February 2017, Pages 149-164.

11. Shao-wei Wang, et al. Rutin inhibits β-amyloid aggregation and cytotoxicity, attenuates oxidative stress, and decreases the production of nitric oxide and proinflammatory cytokines. NeuroToxicology Volume 33, Issue 3, June 2012, Pages 482-490

12. Cohen, Aly. Cognitive dysfunction syndrome. Cornell Richard P. Riney Canine Health Center. Cornell University College of Veterinary Medicine, 2016.