Physicochemical properties and oxidative storage stability of milled roselle (Hibiscus sabdariffa L.) seeds

Milled Roselle (Hibiscus sabdariffa L.) seeds of the UMKL cultivar were analyzed for proximate composition, water and oil absorption capacity, and the influence of storage conditions on storage stability. The storage stability was determined under four types of conditions: light/oxygen (air) (LO), light/nitrogen (LN), darkness/oxygen (air) (DO), and darkness/nitrogen (DN) while monitoring for seven consecutive months. During the storage period, the formation of volatiles was determined using dynamic headspace sampling and Gas Chromatography-Mass Spectrometry (GC-MS) analysis. In total, 85 volatiles were identified, mainly aldehydes, alcohols, ketones, furans, and acids indicating lipid oxidation. It is recommended that milled Roselle seeds should be flushed with nitrogen and stored in darkness. Under these conditions, the seeds can be stored for at least three months without changes in volatile profile. This is important to ensure the good quality of milled Roselle seeds for further commercialization

Influence of Pre-Fermentation Treatments on Wine Volatile and Sensory Profile of the New Disease Tolerant Cultivar Solaris.

Solaris is a new disease tolerant cultivar increasingly cultivated in cool climate regions. In order to explore the winemaking processes' potential to make different styles of Solaris wines, the effects of different pre-fermentation treatments (direct press after crushing, whole cluster press, cold maceration, and skin fermentation) on the volatile profile, chemical, and sensory properties of Solaris wines were investigated. Cold maceration treatment for 24 h and fermentation on skin led to wines with lower acidity and higher glycerol and total polyphenol indexes. Sensory analysis showed that cold maceration enhanced "apricot" and "apple" flavor while skin fermentation gave rise to increased "rose" and "elderflower" flavor. The PLS regression model revealed that fruity flavor of cold macerated wines was related to a combination of esters while β-damascenone and linalool were correlated to the "rose" and "elderflower" flavor. This study provides information about pre-fermentation techniques that allowed the possibility of obtaining wines with different styles