Summary 

Desert Cistanche (Cistanche deserticola Y. C. Ma) is a distinctive medicine–food homology resource from Northwest China's sandy regions, valued for both ecology and nutrition. Turning it into preserved fruit snacks can extend the value chain from raw herb to consumer-ready functional foods.

In this study, we optimized an ultrasonic-assisted sugar infiltration (osmotic infusion) process for Desert Cistanche slices using single-factor experiments and a Box–Behnken response surface design, followed by sensory and quality evaluation. The optimized process produced preserved fruit with a golden-yellow appearance, uniform moisture, a soft-chewy and springy bite, no hard center, and clean sweetness without off-flavors.

 

Cistanche Factory Process

Click to learn more

Optimal conditions:

Sugar permeation time: 60 min

Sugar permeation temperature: 50 °C

Ultrasonic power: 90 W

Impact on sensory score (high → low):
Time > Ultrasonic power > Temperature

This work provides a practical processing reference for functional Cistanche preserved fruit and supports high-value utilization of Desert Cistanche resources.

Keywords (SEO): Desert Cistanche preserved fruit, Cistanche deserticola snack, ultrasonic sugar infiltration, ultrasound osmotic dehydration, medicine–food homology, phenylethanoid glycosides, echinacoside, acteoside, functional preserved fruit, Cistanche processing technology

 

1. Why Develop Desert Cistanche into Preserved Fruit?

1.1 What is Desert Cistanche (Cistanche deserticola)?

Cistanche deserticola is a perennial parasitic herb in the Orobanchaceae family, mainly parasitizing Haloxylon ammodendron roots. It is a high-value traditional Chinese medicinal material, with fleshy scales arranged neatly on the outside.

Globally, about 20 Cistanche species occur mainly across arid regions of Eurasia and North Africa. In China, the two common types are Desert Cistanche and Tubulosa Cistanche.

Importantly for product developers: Desert Cistanche was officially included in China's "medicine–food homology" list on November 17, 2023, which strengthens its positioning for functional foods and daily-health snack formats.

1.2 Functional value and major bioactives (why consumers care)

Desert Cistanche is known for rich nutritional and functional components, including:

Phenylethanoid glycosides (PhGs) (often represented by acteoside/verbascoside and echinacoside)

Polysaccharides

Iridoids

Lignans

Trace elements

These compounds are frequently associated (in research contexts) with antioxidant, anti-inflammatory, anti-apoptotic, and memory-support potential-making Cistanche a promising ingredient for modern functional snacks.

Table 1. Sensory scoring criteria for desert C. deserticola preserved fruit

Item (20 points each)	Scoring criteria	Score range
Taste/Flavor	Sweet–sour balanced; rich and mellow flavor; pleasant sweetness	16–20
	Sweet taste present but flavor is slightly bland; no aftertaste	10–15
	Overly sweet or overly sour; poor flavor	0–9
Texture/Mouthfeel	Moderate softness; good mouthfeel; compact/elastic tissue	16–20
	Slightly soft or slightly firm; good mouthfeel; relatively compact tissue	10–15
	Too hard or too soft; poor mouthfeel; coarse tissue	0–9
Appearance	Good plumpness/fullness	16–20
	Relatively good plumpness	10–15
	Poor plumpness	0–9
Color	Light yellow; uniform; no sugar crystallization ("sandiness")	16–20
	Dark yellow; relatively uniform; none or slight sugar crystallization	11–15
	Dark yellow; non-uniform; obvious sugar crystallization	0–9
Aroma	Strong and pure fruity aroma; no off-odors; long-lasting aroma	16–20
	Lighter fruity aroma or slightly caramel-like; no off-odors	10–15
	No fruity aroma, or sour/burnt/sulfur-like off-odors	0–9

2. Why Ultrasonic Sugar Infiltration for Preserved Fruit?

Preserved fruit is a classic category in China and remains popular, especially reduced-sugar versions. During preserved fruit manufacturing, sugar infiltration is essential to:

inhibit microbial growth (preservation effect)

improve flavor and mouthfeel

stabilize texture

Common infiltration technologies include:

microwave sugar infiltration

vacuum sugar infiltration

ultrasonic sugar infiltration

Microwave methods can lead to poorer color and higher browning. Vacuum infiltration offers fast, uniform penetration. Ultrasound, however, is widely used because it can create microscopic channels and accelerate mass transfer between tissue water and the infusion solution-often improving comprehensive quality.

Table 2. Factors and levels for the Box–Behnken design

Level	A: Sugar permeation time (min)	B: Sugar permeation temperature (°C)	C: Ultrasonic power (W)
-1	50	45	80
0	60	50	90
1	70	55	100

3. Materials, Instruments, and Processing Flow (Factory-Friendly)

3.1 Raw materials

Desert Cistanche from Hotan, Xinjiang, China

70 °Brix concentrated apple juice (used as the sugar solution; lab-prepared)

3.2 Key reagents

Vitamin C, citric acid, sodium chloride, gallic acid, ethanol, Folin reagent, sodium carbonate, rutin, sodium nitrite, aluminum nitrate, sodium hydroxide, oxalic acid, and 2,6-dichlorophenolindophenol (all analytical grade).

3.3 Equipment (industrial relevance)

Main instruments used include:

ultrasonic processor (KH-800KDB)

drying oven

texture analyzer

colorimeter

GC–MS and LC–MS systems for aroma and bioactives

potentiometric titrator, UV–Vis spectrophotometer, centrifuge

 

Table 3. Results of the response surface experiment

Run	A (coded / actual, min)	B (coded / actual, °C)	C (coded / actual, W)	Sensory score
1	0 (60)	-1 (45)	1 (100)	77.4
2	-1 (50)	0 (50)	1 (100)	77.8
3	1 (70)	0 (50)	-1 (80)	73.2
4	-1 (50)	1 (55)	0 (90)	76.2
5	1 (70)	-1 (45)	0 (90)	79.8
6	0 (60)	-1 (45)	-1 (80)	76.2
7	0 (60)	0 (50)	0 (90)	86.0
8	1 (70)	1 (55)	0 (90)	73.6
9	0 (60)	0 (50)	0 (90)	87.8
10	-1 (50)	-1 (45)	0 (90)	74.0
11	0 (60)	0 (50)	0 (90)	85.4
12	-1 (50)	0 (50)	-1 (80)	73.8
13	0 (60)	0 (50)	0 (90)	86.2
14	0 (60)	1 (55)	1 (100)	76.4
15	0 (60)	0 (50)	0 (90)	83.8
16	1 (70)	0 (50)	1 (100)	77.6
17	0 (60)	1 (55)	-1 (80)	75.8

4. Processing Method: Desert Cistanche Preserved Fruit

4.1 Workflow

Selection → Washing → Slicing → Blanching → Sugar infiltration (ultrasound-assisted) → Drying

4.2 Operating points (core production details)

Select uniform, undamaged Cistanche; wash gently to prevent tissue rupture and juice loss.

Peel and slice the Cistanche into uniform slices.

Steam blanch at 100 °C for 120 s.

Use 70 °Brix concentrated apple juice as the infusion solution; perform ultrasonic-assisted sugar infiltration under different conditions.

Dry in an oven at 80 °C for 3 h.

Table 4. Analysis of variance (ANOVA) for the regression model

Source	Sum of squares	df	Mean square	F-value	P-value	Significance
Model	379.52	9	42.17	17.74	0.0005	Significant
A	0.720	1	0.720	0.3028	0.5992
B	3.64	1	3.64	1.53	0.2556
C	13.00	1	13.00	5.47	0.0519
AB	17.64	1	17.64	7.42	0.0296
AC	0.040	1	0.040	0.0168	0.9004
BC	0.090	1	0.090	0.0379	0.8513
A²	122.55	1	122.55	51.55	0.0002
B²	86.98	1	86.98	36.58	0.0005
C²	98.84	1	98.84	41.57	0.0004
Residual	16.64	7	2.38
Lack of fit	8.29	3	2.76			Not significant
Pure error	8.35	4	2.09
Total	396.16	16

Model statistics: R2=0.958R^2 = 0.958R2=0.958, Radj2=0.904R^2_{\text{adj}} = 0.904Radj2​=0.904, Rpre2=0.6322R^2_{\text{pre}} = 0.6322Rpre2​=0.6322
Std. dev.: 1.54; Mean: 78.88; C.V. (%): 1.95

5. Sensory Evaluation (Product-Led Optimization)

Sensory evaluation followed GB/T 10782-2021 using a scoring method. Ten trained panelists evaluated the product; results were averaged.

For commercial development, this is important: sensory score is a practical, consumer-facing index that directly reflects whether the product is attractive in appearance, aroma, taste, and texture.

Table 5. Color analysis of desert cistanche preserved fruit

Parameter	Value
L*	50.46 ± 0.42
a*	-0.71 ± 0.01
b*	15.25 ± 0.38
ΔE	46.40 ± 1.02

 

6. Key Pre-Optimization Steps: Slice Thickness and Blanching Time

6.1 Best slice thickness: 4 mm

Slice thickness was tested at 2, 3, 4, 5, 6, and 7 mm while keeping other conditions constant.

If slices are too thin: structure is damaged, excessive sugar penetration causes overly soft mouthfeel, shrinkage, loss of flavor compounds, and lower yield after drying.

If slices are too thick: sugar infiltration becomes difficult; the center is under-sweetened, texture becomes hard, and color may be less appealing.

Best result: 4 mm thickness, with the highest sensory score (81.2). The product was plump, light yellow, moderately sweet, and pleasantly chewy while maintaining Cistanche character.

6.2 Best blanching time: 20 min

Blanching time was tested at 5, 10, 15, 20, 25, 30 min.

Too short: enzyme inactivation is insufficient; residual polyphenol oxidase promotes browning and darkening; tissue remains dense and resists sugar infiltration; taste can be raw/astringent.

Too long: tissue softens excessively; water-holding declines; collapse and shrink occur; soluble nutrients and flavor compounds leach out; chewiness decreases.

Best result: 20 min, yielding a plump appearance, light yellow color, balanced sweetness, and flexible texture.

 

Table 6. Analysis of aromatic compounds in desert cistanche preserved fruit

No.	RT (min)	Relative content (%)	Compound (English)	Molecular formula	CAS No.
1	13.62	33.9929 ± 0.1680	1-Octanol	C₈H₁₈O	111-87-5
2	15.07	3.1072 ± 0.1401	Isooctanol	C₈H₁₈O	26952-21-6
3	17.21	0.9097 ± 0.0099	1-Octene	C₈H₁₆	111-66-0
4	18.56	47.1520 ± 0.1178	Nonanal	C₉H₁₈O	124-19-6
5	21.72	1.0031 ± 0.0016	Cyclopentadecanol	C₁₅H₃₀O	4727-17-7
6	22.52	0.4175 ± 0.0026	5,6-Epoxy-β-ionone	C₁₃H₂₀O₂	23267-57-4
7	23.43	6.7981 ± 0.0249	Undecanal	C₁₁H₂₂O	112-44-7
8	23.98	0.8613 ± 0.0181	1-Tetradecanol	C₁₄H₃₀O	112-72-1
9	26.73	0.3909 ± 0.0102	Dodecanal	C₁₂H₂₄O	112-54-9
10	27.62	0.3438 ± 0.0092	Decane	C₁₀H₂₂	124-18-5
11	30.12	0.8872 ± 0.0066	Cyclopentadecane	C₁₅H₃₀	4727-17-7
12	31.97	0.7857 ± 0.0039	Pentadecane	C₁₅H₃₂	629-62-9
13	32.50	0.1622 ± 0.0021	Dodecane	C₁₂H₂₆	112-40-3
14	40.06	1.2256 ± 0.0203	Pentadecane	C₁₅H₃₂	629-62-9
15	42.70	0.4593 ± 0.0074	Eicosane	C₂₀H₄₂	112-95-8
16	46.27	0.2887 ± 0.0127	Methyl palmitate	C₁₇H₃₄O₂	112-39-0

7. Optimization of Ultrasonic-Assisted Sugar Infiltration (Core of the Study)

7.1 Single-factor experiments (trend discovery)

Baseline conditions: sugar infiltration time 40 min, temperature 40 °C, ultrasonic power 70 W.

Test factors and levels:

Time: 20, 30, 40, 50, 60, 70 min

Temperature: 30, 35, 40, 45, 50, 55 °C

Ultrasonic power: 50, 60, 70, 80, 90, 100 W

Observed trends:

Sensory score increased and then decreased with longer time; peak at 60 min.

Sensory score increased then decreased with temperature; peak at 50 °C. Higher temperature increases membrane permeability and reduces solution viscosity, enhancing mass transfer-but overly high conditions can harm quality.

Sensory score rose with power in the 60–90 W range and peaked at 90 W.

7.2 Response surface methodology (Box–Behnken design)

Based on single-factor results and to reduce sugar crystallization ("sand returning") while maintaining sensory quality, the sugar solution mass fraction was set at 70%.

Three factors were selected:

A: infiltration time

B: infiltration temperature

C: ultrasonic power

A quadratic regression model was established for sensory score YYY in terms of A, B, and C, showing strong statistical significance and good fit. The analysis indicated that the effects were not purely linear: interactions and non-linear terms were significant.

Factor importance (high → low):
Time > Power > Temperature

7.3 Optimal processing parameters (rounded for production)

Model-predicted optimum was approximately:

60.5 min, 49.6 °C, 91.3 W

For practical manufacturing control, conditions were rounded to:

Time: 60 min

Temperature: 50 °C

Ultrasonic power: 90 W

Validation experiments showed excellent agreement between predicted and measured sensory scores (relative error about 0.4%), indicating the model can guide production.

 

Table 7. Texture analysis of desert cistanche preserved fruit

Parameter	Value
Peel hardness (N)	0.241 ± 0.038
Springiness (mm)	0.822 ± 0.297
Flesh brittleness (g·s)	245.997 ± 19.908
Firmness (g·s)	0.001 ± 0.012

 

8. Quality Evaluation of the Optimized Preserved Fruit

8.1 Color characteristics

Colorimeter results (L*, a*, b*) indicated an overall yellow-brown tone with moderate brightness and minimal green tint-consistent with typical preserved fruit processing characteristics.

 

 

TCM Cistanche extract application

8.2 Volatile aroma composition (GC–MS)

Volatile components were identified and classified into six categories:

aldehydes

alcohols

alkenes

alkanes

ketones

esters

Key sensory interpretation for product development:

Aldehydes (dominant): nonanal, undecanal, dodecanal
These medium-chain fatty aldehydes have low odor thresholds and contribute fatty-sweet, citrusy, waxy, and floral notes. In preserved fruit systems, they often arise from lipid oxidation and/or Maillard-type pathways under heating and high sugar.

Alcohols: iso-octanol, 1-octanol, cyclopentadecanol, 1-tetradecanol
Shorter-chain alcohols add mild sweet/green/citrus notes and roundness. Longer-chain alcohols have low volatility and act as fixatives, supporting lasting aroma.

Alkene: 1-octene
Contributes fresh green notes, helping reduce perceived oiliness.

Alkanes: decane, pentadecane, eicosane
Generally low-aroma, acting more as inert background/volatile carriers.

Ketone: 5,6-epoxy-β-ionone
A classic floral compound with violet-like, sweet fruity, and woody tones, enhancing elegance and complexity.

Ester: methyl palmitate
Typically weak waxy/fruity background; limited direct impact but contributes to the overall matrix.

Overall, the optimized product showed a rich, rounded aroma dominated by aldehydes, supported by floral/fruity nuance and longer-lasting after-notes-suggesting good aroma quality for snack commercialization.

8.3 Texture profile

Under the optimized process:

the surface showed low hardness (soft exterior)

elasticity was moderate (partial recovery after compression)

the flesh was extremely soft with very low firmness

From a product design standpoint, this indicates a soft-chewy style preserved fruit, but also suggests that structural reinforcement (if needed) may require adjustments in drying curve, slice thickness distribution control, or post-infusion setting.

8.4 Physicochemical properties

Results indicated:

moisture content met relevant national standards; drying level was appropriate

dehydration ratio was moderate

rehydration performance was excellent (consistent with a looser internal structure)

soluble solids increase improved sweetness and mouthfeel

total acidity was moderate

vitamin C content was low (likely due to thermal sensitivity during processing)

Overall, the physicochemical quality was good, with vitamin C being the weaker point-common in heat-processed preserved fruit.

8.5 Functional components (bioactive retention)

The preserved fruit retained measurable functional components:

total phenylethanoid glycosides (PhGs): about 0.797%

total flavonoids and total polyphenols were detected

total sugar was high (49.21 g/100 g), consistent with preserved fruit characteristics

This supports the feasibility of producing a functional-style Cistanche preserved fruit that maintains signature bioactive markers while delivering snack-friendly taste.

Table 8. Physicochemical properties of desert C. deserticola preserved fruit

Item	Value
Moisture content (%)	23.19 ± 0.42
Water loss rate (%)	20.7 ± 0.6
Rehydration ratio (%)	128.3 ± 0.6
Increase in soluble solids (%)	34.5 ± 0.6
Total acidity (g/kg)	13.60 ± 0.26
Vitamin C (mg/100 g)	1.10 ± 0.03

 

9. Conclusions (What this means for Cistanche factories and product teams)

Using Desert Cistanche as the raw material, we developed a functional preserved fruit product using an ultrasonic-assisted sugar infiltration approach. By combining single-factor experiments and Box–Behnken response surface optimization with sensory scoring as the core indicator, the best process was confirmed as:

60 min infiltration time

50 °C infiltration temperature

90 W ultrasonic power

The product produced under these conditions exhibited:

natural golden-yellow color, uniform appearance, moist texture

clean sweetness without off-flavors

soft, chewy, springy bite without a hard core

overall excellent sensory quality

The established regression model fit well and can be used for stable process control and scale-up guidance. As the medicine–food homology industry continues to grow, Desert Cistanche preserved fruit shows strong commercial potential and can help integrate desert ecological industries with modern functional food manufacturing.

 

Table 9. Bioactive compounds in desert C. deserticola preserved fruit

Item	Value
Acteoside / Verbascoside (%)	0.158 ± 0.014
Echinacoside (%)	0.639 ± 0.034
Total flavonoids (%)	1.072 ± 0.005
Total polyphenols (%)	0.07788 ± 0.001
Total sugars (g/100 g)	49.21 ± 0.160