Assessment of physical, microstructural, thermal, techno-functional and rheological characteristics of apple (Malus domestica) seeds of Northern Himalayas.

In this research, two common apple seed cultivars Viz: 'Golden Delicious' (GD) and 'Red Delicious' (RD) of Northern Himalayan region were characterized for physical, techno-functional, microstructure, thermal, and rheological properties. Seeds showed a significant difference in width, arithmetic, and geometric mean diameters, volume, and surface area. Proximate analysis results revealed that seed flours have high oil content (> 20%) and are potentially rich sources of protein (> 40%). Color analysis of flours indicated their satisfactory whiter color with higher brightness values (L* ˃ 75), resulting from the reduced particle size which allows greater light penetration and relatively lower a* (< 1.5) and b* (< 11) values. Techno-functional attributes including water/oil absorption capacity, emulsifying capacity, and emulsion stability were significantly higher in RD than GD flour. There was also a significant difference in the average particle size of seed flours. Flour micrographs indicated the presence of oval/spherical-shaped starch granules embedded in dense protein matrix while, Differential Scanning calorimeter (DSC) revealed exothermic transition enthalpies for seed flours. Additionally, seed flours depicted high elastic modulus (G'), suggesting their suitability for modifying food texture. It was concluded that apple seeds exhibit significant potential for use in formulating protein-enriched foods while contributing to reducing industrial wastage.

Exploring bud dormancy completion with a combined architectural and phenological analysis: the case of apple trees in contrasting winter temperature conditions.

PREMISE OF THE STUDY: The branching pattern and phenology of trees result from interactions between the tree's genetic constitution and environmental conditions. Temperature strongly affects the duration of bud dormancy and further shoot growth. Our hypothesis was that shoot architecture is strongly affected by winter temperatures determining both the position and budburst of vegetative laterals with a lower effect on their outgrowth. METHODS: The study was conducted on four apple cultivars characterized by various chilling requirements and grown in two contrasting winter temperature conditions. A two-step approach was designed to quantify at the shoot scale first the branching pattern and second two phenological stages of vegetative laterals, budburst and outgrowth. A categorical variable, the branching zone, was built to summarize the lateral position along the shoot. It was integrated into the phenological analysis as a factor together with the cultivar and the winter temperature. KEY RESULTS: Temperature had a main effect on the distribution of vegetative laterals along the shoot. It also strongly affected budburst, which was also affected by the cultivar and the branching zone. The outgrowth of the lateral was not significantly affected by temperature but was significantly affected by the cultivar and the branching zone. Furthermore, the delayed senescence and subsequent leaf persistence during winter, characterizing the apple tree in the mild winter temperature condition, had only a weak effect on the distribution of vegetative laterals and on budburst and lateral outgrowth. CONCLUSIONS: The actual shoot architecture and budburst result from an ordered sequence of events with a pivotal role of winter temperatures on the dormancy completion of individual lateral buds. Endogenous factors related to the cultivar branching pattern overtake the temperature effect on the lateral outgrowth.

Similarities and gradients in growth unit branching patterns during ontogeny in "Fuji" apple trees: a stochastic approach.

This study aims to explore and model the changes in growth unit (GU) branching patterns during tree ontogeny. The question was addressed in apple trees cv. "Fuji", by analysing the relative impact of GU length and within-tree position. The development of two 6-year-old trees was recorded over 6 years. The fate of axillary buds along each GU was represented as a sequence of symbols corresponding to five types of lateral growth: latent buds, short, medium, long, and floral lateral GUs. Based on an exploratory analysis of data and a priori hypotheses, a hidden semi-Markov chain was estimated from all of these GU sequences. This model was composed of six transient states representing successive branching zones along the GUs. The accuracy of this global model was a posteriori assessed by fitting the characteristic distributions computed from model parameters to the corresponding empirical characteristic distributions extracted from the observed sequences. The observed sequences were then grouped hierarchically according to the GU length, year of growth, and branching order. Comparing model parameters between these sub-groups revealed similarities between GUs. These similarities were based on particular branching zones whose composition and relative position within the GUs remained invariant across the subgroups: the latent zones, floral zone, and short-lateral zone. The probability of occurrence of the floral zone varied with the year, showing the alternate fruiting of "Fuji". It is shown that, during tree ontogeny, as GU length decreases, branching patterns tend to progressively simplify due to the disappearance of the most central zones and a progressive reduction in the length of the floral zone.