Browsing by Author "Gong, Wei"

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    Chemometric and sensory characterisation of New Zealand craft ciders : a preliminary study : a thesis presented in partial fulfilment of the requirements for the degree of Master of Food Technology at Massey University, Manawatu Campus, Palmerston North, New Zealand
    (Massey University, 2024) Gong, Wei
    The New Zealand craft cider industry is growing, but its unique sensory characteristics and chemical components are not yet fully scientifically understood. This study aimed to understand the key components and sensory attributes that define selected New Zealand craft ciders through the integration of chemometrics and sensory characterisation. Seventeen craft cider samples were collected from New Zealand cider regions and characterized for their chemical parameters, including pH, titratable acidity, tannin content and colour. Volatile components were identified and quantified using headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS). One focus group (n=5) was organised to generate consumer-oriented descriptors for ciders. This was followed by quantitative sensory evaluation using a 9-point hedonic scale for liking of sensory attributes and Check-All-That-Apply (CATA) to characterise the samples. The results of the data analysis showed that there were significant differences (p<0.05) in chemical parameters and volatile components among the samples. Principal component analysis (PCA) revealed that tannin, pH and colour (a* and b* values) were the chemical parameters that contributed to high variability among the samples. The key volatile compounds identified in the samples were ethyl octanoate, isoamyl octanoate, and 1-octanol. According to sensory assessments, ciders from the North Island were mainly described as "fruity," whereas those from the South Island were primarily described as "bitter" and "dry." Additionally, the study showed that while bitterness and astringency were negative drivers, fruitiness and sweetness were positive drivers of acceptance for the samples. Moreover, the North Island's ciders displayed higher levels of similarity, whilst the South Island's ciders displayed higher levels of chemical variety. This finding implies that production techniques and apple varieties may be significant variables in determining the sensory and chemical profiles of the samples. This has implications for the importance of understanding the impact of geographical factors on the chemical and sensory characteristics of craft ciders. This study not only revealed differences in chemical and sensory characteristics of New Zealand craft cider but also provided valuable insights for producers. Future research could further explore the effects of apple variety, production methods and regional characteristics on cider quality, thereby contributing to the sustainable development of the New Zealand craft cider industry.