Pecans are the fruits of the American hickory (Carya illinoinensis), also known as thin-shelled hickory nuts. They are native to the United States and northern Mexico and have been introduced and cultivated in the Yangtze River basin of China in recent years. Pecans are recognized as one of the world’s top ten nuts [1–3]. They are highly nutritious: the kernels contain abundant oils and proteins, as well as vitamins and minerals, and are traditionally associated with benefits such as supporting brain function and kidney health.
In general, the husk, shell, and kernel of hickory nuts have been utilized based on their nutritional and chemical composition, and products such as hickory powder, walnut-kernel snack foods, and hickory oil have been reported. However, pecans have a relatively short cultivation history in China. While there are many reports on cultivation and planting, research on processing and utilization remains limited. Salt-baked pecans are a popular traditional dried-nut snack, yet their processing is often informal, and product quality and nutritional value are not clearly defined. Therefore, this study optimized the processing conditions for salt-baked pecans through single-factor experiments and response surface methodology, and analyzed the nutritional composition of the final product, aiming to provide a theoretical basis for quality improvement.
Preparation Process of Salt-Baked Pecans
Processing flow:
Pecans → Shell cracking → Salt baking (salt simmering) → Drying → Cooling → Packaging → Finished product
Single-Factor Experimental Design for Process Optimization
1) Salt addition (salt simmering conditions)
A pre-boiling spice solution was prepared containing Sichuan peppercorn (1.5 g/100 g), star anise (3 g/100 g), and cinnamon (4 g/100 g). Pecans were simmered in this solution with different salt levels for 20 min. Salt addition levels were 5 g/100 g, 10 g/100 g, 15 g/100 g, and 20 g/100 g. After simmering, the pecans were dried at 100°C for 150 min, cooled, and evaluated by sensory assessment.
2) Pre-boiling time
Pecans were boiled for 10 min, 15 min, 20 min, 25 min, and 30 min. After boiling, the samples were dried at 100°C for 150 min, cooled, and evaluated by sensory assessment.
3) Drying time and temperature
After determining the optimal pre-boiling parameters, pecans were dried at 80°C and 100°C for 30 min, 60 min, 90 min, 120 min, 150 min, 180 min, 210 min, and 240 min, then cooled and evaluated by sensory assessment.
Sensory evaluation was conducted based on the industry standard for pecan sensory assessment in SB/T 10556—2017 [9], combined with practical scoring conditions.
Table 1. Sensory Scoring Criteria for Salt-Baked Pecans
| Category | Appearance (30 points) | Kernel size & integrity (30 points) | Texture & aroma (40 points) |
|---|---|---|---|
| High score | Shell is brown to dark brown; kernel is purplish-brown or dark red; uniform color (21–30) | Uniform size; relatively intact shape (21–30) | Clean aroma and crisp texture; pure nut flavor; no off-odors (26–40) |
| Medium score | Shell is brown to dark brown; kernel is purplish-brown or dark red; uneven color (11–20) | Uneven size; shape still relatively intact (11–20) | Pleasant aroma and acceptable texture; nut flavor present; slight burnt note (13–25) |
| Low score | Kernel is very dark/black; clear burnt condition (0–10) | Size highly inconsistent; many incomplete nuts (0–10) | Rancid or burnt odor; poor palatability (1–12) |
Key Findings
As salt content increased, the sensory score first increased and then decreased, reaching the highest value at 15 g/100 g. This is because pecan seed coats contain astringent substances such as tannins, catechins, pyrogallol and its derivatives, and juglone-related compounds [10–11], resulting in strong astringency in plain pecans. With increased salt addition, the soaking solution concentration rises and penetrates the kernel more easily, helping reduce astringency. However, excessive salt causes overly salty kernels and reduces palatability.
The effect of drying time on sensory quality also showed a pattern of first increasing and then decreasing. In addition, the peak at 100°C occurred earlier than at 80°C. The highest sensory scores were achieved with drying at 100°C for 150 min and 80°C for 210 min, indicating that high-temperature/short-time drying and low-temperature/long-time drying both support desirable flavor development. Under these conditions, the product was crisp and palatable, had a clean nut aroma, showed intact kernel structure, and had no rancid or burnt notes.
Conclusion
Overall, salt-baked pecans showed the best sensory quality under the following conditions: salt addition 15 g/100 g, boiling time 20 min, and drying at 100°C for 150 min. The resulting product had intact kernels, brownish shell color, reddish-brown kernels with uniform appearance, a crisp texture, no rancid or burnt odors, and a strong, characteristic pecan aroma.
At these optimal conditions, the product had 1.2% moisture, 7.82% protein, 66.50% fat, and an acid value of 1.24 mg/g, meeting the physicochemical requirements for pecans in SB/T 10556—2009. The essential amino acid content was 2.37 g/100 g, accounting for 43.57% of total amino acids. The unsaturated fatty acid content was as high as 91.25%, and essential fatty acids—mainly linoleic acid and linolenic acid—reached 20.32%, indicating strong nutritional value.
However, during commercialization, further research is needed on storage stability under different packaging conditions and on methods to control quality during storage.
