Hodnocení kvality kokosů a diagnostika
Raman spectroscopy in combination with chemometrics on coconut water
- Quantification of adulteration of fresh coconut water by dilution, and its masking with sugars
- Coconut water was extracted from young Costa Rican coconuts and heat treated to emulate pasteurization
- Samples were then adulterated by dilution with water and single sugars, mixtures of sugars, and high-fructose corn syrup (HFCS)
- Total of 155 samples were analysed with Raman spectroscopy at 785?nm excitation and 620 spectra analysed with chemometrics
- Successful quantification of
- Dilution and adulteration with single sugars between 1.9 and 2.6% [35]
- Masking of dilution with mixtures of sugars at 9.8%
- Masking of dilution with HFCS at 7.1%
- Raman spectroscopy has significant potential as a rapid accurate analytical method for the detection of adulteration in this product
Quality of VCO
- Appointed by Asian Pacific Coconut Community (APCC) standards
- Different types of raw materials, namely incubated and desiccated coconut meat, incubated coconut milk as well as freeze-thawed coconut milk affected physicochemical properties of VCO (Marina et al., 2009b) [30]
- no drastic differences in overall VCO quality were observed
- Physical and chemical qualities must comply with the Philippine standards for VCO and the Codex standard for coconut oil (Dia, Garcia, Mabesa, & Tecson-Mendoza, 2005) [30]
- Mansor et al. (2012) characterized VCO obtained from different methods including chilling, fermentation, fresh-drying, and enzyme treatment
- Various methods slightly affected the quality but the difference was not significant
- The FFA, peroxide, iodine, and saponification values [30]
- Reported for commercial VCO samples were in accordance with the specification guided by Codex standard (2003) for refined coconut oil.
- Senphan and Benjakul (2015) also stated that VCO extraction aided by Alcalase (10 unit/g protein) or crude protease extract (from the hepatopancreas of Pacific white shrimp) at 60 °C for 90 min had no influence on the resulting VCO quality. [30]
- Patil et al. (2016) studied characteristics as well as the quality of VCO as influenced by maturity stages. Maturity stages of coconut had no profound effect on oxidative stability and quality of VCO. [30]
Essential composition and quality parameters of virgin coconut oil (VCO) appointed by Asian Pacific Coconut Community (APCC)
- 1. Moisture (%) Max 0.1
- 2. Refractive index at 40°C 1.4480–1.4492
- 3. Relative density 0.915–0.920
- 4. Specific gravity at 30°C/30°C 0.915–0.920
- 5. Iodine value (g I2/100 g oil) 4.1–11
- 6. Saponification value (mg KOH/g oil) 250–260
- 7. Free fatty acid (%) Max 0.2
- 8. Peroxide value (meq O2/kg) Max 3 [30]
- Marina, Che Man, Nazimah, and Amin (2009a) reported the fatty acid composition of commercial VCO available in Malaysia and Indonesia
- Lauric acid (46% to 48%) was dominant fatty acid and the content
- Was within the standard limit for VCO according to Asian and Pacific Coconut Community (APCC, 2003) [30]
- And Malaysian Standard (2007)
- Lauric acid (with the range of 46.36% to 48.42%) was found in all VCO samples [30]
- VCO separated from coconut milk with three different maturity stages had a similar fatty acid composition (Patil et al., 2016) [30]
