Describing the Sensory Complexity of Italian Wines: Application of the Rate-All-That-Apply (RATA) Method

The aim of this study was to characterise a large and heterogeneous Italian wine sample applying the Rate-All-That-Apply method (RATA) with semi-trained judges. Twelve judges evaluated 46 samples including white, red, rosé and sparkling wines in two replicates. Judges were asked to select from a list of descriptors all the sensations that described the samples and to evaluate their intensity. Judges obtained high repeatability index scores. A good panel reliability was also highlighted in terms of the reproducibility of the whole sensory characterisation through a multi-factor analysis (MFA). MFA results also showed a good discriminatory ability of the panel with red wines described by bitterness, astringency, body, alcohol and specific olfactory stimuli such as red fruits, spicy and roasted, while white wines were salty, sour and characterised by citrus, tropical fruits and white flowers odours. The RATA method is a suitable and reliable methodology for the description of a wide variety of wine samples and a valuable alternative approach to conventional descriptive analysis to gather information about the sensory perception of a very complex product even when large panels of consumers are not available. Furthermore, the present results provide useful information for wine producers to characterise their products as well as for the optimisation of production disciplinaries, which currently are not exhaustive in the description and the discrimination among products.

Effect of frozen storage on the inhibition of microbial population, chemical and sensory characteristics of coconut neera

AIM

In this study, the effect of frozen storage on the inhibition of microbial population in coconut neera for shelf life extension was analysed.

METHODS AND RESULTS

The aliquots of fresh neera were frozen at -6 and -20°C. The microbial reduction and chemical qualities were analysed during storage days, and were compared with the control. The highest reduction in microbes was obtained at -20°C for lactic acid bacteria, yeast and total viable count. Moreover, the fluorescence cell staining and cell density analysis exhibited a decline at -20°C, however it showed higher at -6°C. At the end of 28 days, neera exhibited a pH of 5·37, total soluble solid of 14·0 °Brix and total acidity of 0·82 mg l^-1 at -20°C. Besides, color, viscosity, total protein and ethanol showed a less difference with control and better sensory attribute up to 21 days at -20°C.

CONCLUSIONS

Frozen storage at -20°C resulted in a better inhibition of lactic acid bacteria, which preserves neera from the metabolic conversion. The physicochemical qualities of neera were preserved for a longer period when stored at -20°C than at atmospheric storage.

SIGNIFICANCE AND IMPACT OF THE STUDY

Frozen storage reduced microbial population and preserves the chemical properties with acceptable sensory attributes and increases the shelf life of coconut neera, making it fit for consumption.

Identification of the Volatile Compounds and Sensory Attributes of Long-Term Aging Vin Santo Wine from Malvasia di Candia Aromatic Grapes

In an effort to offer a contribution to fill the gap of knowledge about the relationship between the sensory properties and aromatic profile of Malvasia grapes, the present work was aimed at evaluating volatile compounds, aroma, and sensory attributes of long-term aging (15 years) Vin Santo wine obtained from Malvasia di Candia aromatica grapes. In this article, the aromatic profile are studied using gas chromatography-mass spectrometry (GC-MS), gas chromatography with flame ionization detection (GC-FID), and sensory analysis by involving a panel of trained assessors to explore the sensory profile resulting after long-term aging (up to 15 years). The GC-MS and GC-FID analyses of wines allowed the identification and semi-quantification of twenty-seven volatiles belonging to 12 conventional groups of compounds. From a sensory perspective, the Vin Santo wines analyzed in this study presented a very complex sensory profile characterized by 19 sensory descriptors of which 14 related to olfactory terms. The relationship between sensory and GC-FID data deduced from three samples representing nearly three years in the past 15 years was investigated by means of Partial Least Square (PLS) modeling, showing that specific volatile compounds could predict a specific orthonasal and/or retronasal odor perceived by the trained panel of assessors, clearly differentiating the Vin Santo vintages. Identifying the main volatiles and aromas of long-term Vin Santo wine may be helpful to winemakers, since wine aging sensory properties are often associated with a prestigious image and contribute to defining wine quality.