Chemical Markers of Shiikuwasha Juice Adulterated with Calamondin Juice

Abstract

Detection of shiikuwasha (Citrus depressa Hayata) juice adulterated with calamondin (Citrus madurensis Lour.) juice was investigated by the analyses of (1) phloretin dihydrochalcone glucoside, 3',5'-di-C-β-glucopyranosylphloretin (PD) detected by thin-layer chromatography and high-performance liquid chromatography (HPLC), (2) polymethoxylated flavones (PMFs), included nobiletin, tangeretin, and sinensetin, detected by HPLC, and (3) γ-terpinene peak percentage obtained by headspace solid-phase microextraction gas chromatography with cryofocusing. PD was detected in calamondin juice (25.5 mg/100 mL) but not in shiikuwasha juice. Shiikuwasha juice contained higher levels of nobiletin (48.8 mg/100 mL) than calamondin juice (2.4 mg/100 mL). Shiikuwasha juice was characterized by containing a higher percentage of γ-terpinene (12.3%) than calamondin juice (0.7%). A discrimination function obtained by a linear discriminant analysis with PMFs and a peak ratio of [nobiletin/tangeretin] and γ-terpinene detected the adulteration with accuracies of 91.7%. These three chemical markers were useful to detect shiikuwasha juice that is suspected of being adulterated with calamondin juice.

Detection of Adulterated Shiikuwasha Juice by Sensory Evaluation, Colorimetric Value and Volatile Components

“…These equations were useful for confirming the presence or absence of small amounts (1%) of shiikuwasha juice in calamondin juice. Yamamoto et al (2012) reported γ-terpinene as a chemical marker to detect adulterated shiikuwasha juice. In this study, γ-terpinene and linalool were shown to be new and useful chemical markers for detecting small amounts of shiikuwasha juice in calamondin juice.…”

“…Therefore, shiikuwasha juice adulterated with calamondin juice is difficult to detect. Yamamoto et al (2012) reported the use of 3′,5′-di-C-β-glucopyranosylphloretin, polymethoxylated flavones and γ-terpinene in detecting shiikuwasha juice adulterated with calamondin juice. Although the chemical characteristics of both citruses were revealed, differences in sensory characteristics have not been demonstrated.…”

Optimization of high ultrasound-assisted extraction (INEFU) of active components from natural materials by response HPLC-PDA analysis

“…1. [25]. In addition, HAE extracts contained vitamin C at a very lower percentage than in INEFU extracts (range 0.12~0.23%).…”

“…[11]. Calamondin orange (Citrus madurensis, Citrofortunella microcarpa), which belongs to Citrus Metacitrus Pseudofortunella, ranges from tropical to subtropical areas, including China, Philippines, Central America, Japan, and Hawaii [12]. Calamondin orange contains vitamin C, including tangeretin, and sinensetin, in large quantities in the peel part of this citrus orange [13].…”

Polymethoxyflavones Isolated from the Peel of Miaray Mandarin (Citrus miaray) Have Biofilm Inhibitory Activity in Vibrio harveyi

“…These compounds are also reported to be present in high levels in the fruits of Shiikuwasha (Citrus depressa) and Calamondin (Citrus madurensis). 18,19 In recent years, advances in chromatographic techniques have led to improved methods for the rapid separation and isolation of bioactive compounds. Simultaneously separation and spectroscopic detection methods, termed hyphenated chromatography, can be used to elucidate the tentative identity of the compounds of interest.…”