This study describes the application of the laser photoacoustic spectroscopy (PAS) for quantification of total carotenoids (TC) in corn flours and sweetpotato flours. Overall, thirty-three different corn flours and nine sweetpotato flours were investigated. All PAS measurements were performed at room temperature using 488-nm argon laser radiation for excitation and mechanical modulation of 9 and 30 Hz. The measurements were repeated within a run and within several days or months. The UV–Vis spectrophotometry was used as the reference method. The concentration range that allows for the reliable analysis of TC spans a region from 1 to 40 mg kg⁻¹ for corn flours and from 9 to 40 mg kg⁻¹ for sweetpotato flours. In the case of sweetpotato flours, the quantification may extend even to 240 mg kg⁻¹ TC. The estimated detection limit values for TC in corn and sweetpotato flours were 0.1 and 0.3 mg kg⁻¹, respectively. The computed repeatability (n = 3–12) and intermediate precision (n = 6–28) RSD values at 9 and 30 Hz are comparable: 0.1–17.1% and 5.3–14.7% for corn flours as compared with 1.4–9.1% and 4.2–23.0% for sweetpotato flours. Our results show that PAS can be successfully used as a new analytical tool to simply and rapidly screen the flours for their nutritional potential based on the total carotenoid concentration.

中文翻译：

---

用激光光声光谱法测定玉米粉和甘薯粉中的总类胡萝卜素。


本研究描述了激光光声光谱 (PAS) 在玉米粉和甘薯粉中总类胡萝卜素 (TC) 定量中的应用。总体而言，研究了三十三种不同的玉米粉和九种甘薯粉。所有 PAS 测量均在室温下使用 488 nm 氩激光辐射进行激发以及 9 和 30 Hz 的机械调制。在一次运行中以及几天或几个月内重复测量。使用紫外-可见分光光度法作为参考方法。能够对玉米粉进行可靠分析的 TC 浓度范围为 1 至 40 mg kg ^-1 ，甘薯粉的浓度范围为 9 至 40 mg kg ^-1 。对于甘薯粉，定量甚至可以扩展到 240 mg kg ^-1 TC。玉米和甘薯粉中 TC 的估计检出限分别为 0.1 和 0.3 mg kg ^-1 。 9 Hz 和 30 Hz 时计算的重复性 ( n = 3–12) 和中间精度 ( n = 6–28) RSD 值具有可比性：玉米粉为 0.1–17.1% 和 5.3–14.7%，而玉米粉为 1.4–9.1% 和红薯粉为 4.2–23.0%。我们的结果表明，PAS 可以成功地用作一种新的分析工具，根据总类胡萝卜素浓度简单快速地筛选面粉的营养潜力。