Influence of Pretreatments on Quality Parameters and Nutritional Compounds of Dried Galega Kale (Brassica oleracea L. var. acephala)

Characterization of key aroma compounds of fried pepper sauce under different pretreatment processes

Fried pepper sauce (FPS) is renowned among consumers for its distinct aroma profile and rich nutritional composition. However, the primary aroma components of FPSs, crucial for quality assurance, remain unclear. Therefore, this study aimed to delve deeper into the unique aroma profile of FPSs by analyzing samples subjected to various pretreatment methods (including three heat-moisture treatment processes: soaking at 60 °C, soaking at 100 °C, and steaming, and three crushing processes: mashing, mincing, and horizontal knife cutting). FPS samples were analyzed by quantitative descriptive sensory analysis (QDA), gas chromatography-olfactometry-mass spectrometry (GC-O-MS), relative odor activity value analysis (rOAV), principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA) and partial least squares regression analysis (PLSR). The QDA results revealed that the overall aroma profile of FPS products was characterized by chili-like, fatty, and herbal notes. GC-MS identified 115 volatile components in FPSs, primarily alkenes, ketones, and acids, with varying concentrations across samples. According to the rOAV (>1) and GC-O, 11 compounds were identified as key aroma contributors to FPS aroma, including 2-methylpropanal, acetic acid, 3-methylbutanal, methional, eucalyptol, benzeneacetaldehyde, linalool, (E)-2-nonenal, (2E)-2-decenal, (2E,4E)-deca-2,4-dienal, and (E,Z)-2,4-decadienal. PCA and PLS-DA were employed to assess aroma differences among nine FPS samples. Screening for VIP > 1 and p < 0.05 identified 8 and 12 key marker compounds influenced by different crushing methods or heat-moisture treatments, respectively. PLSR indicated that the sensory attributes were greatly related to most aroma-active compounds. These findings provide novel insights into FPS aroma attributes, facilitating precise processing and quality control of fried pepper sauce products.

EFFECT OF ULTRASOUND AND ACID PRETREATMENTS DURING DEHYDRATION ON QUALITY PROPERTIES OF QUINCE

Several methods are employed to remove the moisture from organic or non-organic materials, in a variety of industrial applications. Among all, dehydration of fruits is an alternative to decline post-harvest loss of fruits and also a process to produce dried fruits, which can be directly consumed or become part of foodstuffs like cakes, and many others. In particular, drying provokes a series of changes in materials, such as oxidation, browning, or loss of nutritional-functional properties. Ultrasound is famous to have a significant effect on the rate of various processes. Quince is a fruit which is rich in polyphenols, organic acids, and amino acids with important health benefits. The present study examined the effect of ultrasound and blanching pre- treatments prior to convective drying on quality  properties  of dehydrated quince slices. A completely randomized design was used to address the effect of time of sonication (10−30 min), temperature (40−60°C), and anti-browning agents including acetic, citric, and ascorbic acids as well as distilled water on quality properties of dehydrated quince slices. The obtained results revealed that the shortest drying time (270.33±35.59 min) and the highest total phenolic content (57.29±12.72 mg GAE/ml) were recorded for samples exposed to the ascorbic acid solution. Comparison of the pre-treated and control samples indicated that the highest rehydration ratio (2.75±0.29 %) was achieved by blanched samples in acetic acid solution. The use of citric acid solution led to the highest score in the taste (3.45±1.1), color (3.84±0.9), and texture (3.47±1.02) of quince slices on the basis of a 5- point hedonic scale. The obtained results depended on both ultrasound and the type of blanching solution. Citric and acetic acid samples indicated the highest values of the sensory evaluation and water loss, respectively.

Evaluation of Drying and Storage Conditions on Nutritional and Sensory Properties of Dried Galega Kale (Brassica oleracea L. var. Acephala)

This work evaluated the effect of the air-drying temperature and vacuum packaging on quality and nutritional compounds of dehydrated galega kale, previously steam blanched, during 5 months of storage. When compared with the vacuum packaged kale, the packaging without vacuum yielded improved nutritional features, in general. This approach combined with a drying temperature of 40°C resulted in retention percentages of 62, 38, 92, and 48% for vitamin C, total phenolic content, total antioxidant capacity, and chlorophylls, respectively. The acceptance of the dried product by the consumer was assessed through a focus group. The participants classified the product as a practical and convenient alternative to cook healthier dishes. The appearance of dried galega kale was described as being fragile and being with nice smell, natural colour, and flavour similar to the fresh product. In conclusion, the herein presented product was addressed as an innovation with multiple possible applications in several recipes.