Development of Innovative Candied Chestnuts from Three Chestnut Cultivars Grown in Portugal

Abstract

The main purpose of this work is the development of a value-added product (candied chestnuts) from Portuguese chestnut (Castanea sativa) cultivars (Martainha, Longal and Judia), as a way to minimize product loss and wastes. To accomplish this goal, the effects of rehydration, cooking, and syrup conditions on composition, textural properties, and colour parameters of candied chestnuts were investigated. The obtained results revealed that the optimal conditions to prepare candied chestnuts with a sweet taste, dark brown colour, with a crispy texture on the outside and smooth texture in the inner flesh were rehydration at 45 °C for a period of 5 h, cooking in a pressure pan for 15 min, and an immersion process with sucrose syrup for two days (syrup with 25% of sucrose on the first day and syrup of 50% of sucrose on the second day). During the process, the drying loss, hydration ratio, and cooking gain of the different cultivars were about 90%, 79%, and 130%, respectively. The total colour difference of candied chestnuts ranged from 24.18 (Longal) to 29.95 (Judia), the stickiness was moderately intense, and the adhesiveness was high for the three varieties. Longal candied chestnuts were the softest and Martainha candied chestnuts were the hardest, the most elastic, and cohesive. Moreover, the candied chestnuts presented a moisture content ranging from 52.70% and 54.23%, amounts of carbohydrates in the range of 88.58 to 91.87 g/100 g d.m, values of protein (6.55–9.51 g/100 g d.m.), values of ash (0.78–1.98 g/100 g d.m.), and fat (0.87–1.58 g/100 g d.m.). In conclusion, the chestnuts of Portuguese cultivars Martainha, Longal and Judia reveal a good potential to produce candied products with high added value.

Controlled Atmosphere Improves the Quality, Antioxidant Activity and Phenolic Content of Yellow Peach during the Shelf Life

“…The total chromatic difference (∆E) is calculated using Formula (4). Based on the different degrees of yellow peach color, the ∆E is divided into three levels [ 24 ], 0.0 < ∆E ≤ 2.0 corresponds to Class 0, representing color difference is almost invisible to human vision; 2.0 < ∆E ≤ 3.5 corresponds to Class 1, which means that most people cannot identify color difference and professionally trained people can identify it; 3.5 < ∆E corresponds to Class 2, representing color difference can be distinguished. The ∆E is obtained as follows: …”

Sweet Chestnut (Castanea sativa Mill.) Nutritional and Phenolic Composition Interactions with Chestnut Flavor Physiology

“…Studies indicate that the CD36 transporter, protein, which is found in taste buds, specifically in the circumvallate and leaf papillae [ 85 ], and the G protein-coupled receptor (GPCR) is the most likely candidate receptors in taste cells, with various taste transduction mechanisms also involved [ 86 ]. Chestnut fruit includes relatively low unsaturated fatty acids (oleic, linoleic, and palmitic acids) [ 8 ]. Studies indicate that roasting chestnuts decreases the concentration of unsaturated and saturated fatty acids.…”

“…On the other hand, they may be related to differences in post-harvest, storage, and processing [ 107 ]. In recent years, consumers have preferred healthy, fresh, and high-quality food, and chestnuts have high amounts of healthy bioactive metabolites and nutritional qualities, capable of improving the performance of the human body [ 3 , 8 , 26 ]. Moreover, chestnuts are very versatile when it comes to cooking, they can be present in numerous dishes or consumed alone as a snack.…”

“…Sweet chestnut varieties are generally classified according to their geographical origin and morphological and phenological characteristics. They can be divided into several groups depending on the primary use of their fruits; some varieties produce chestnuts that are ideal for fresh and sweet commercialization, while others are more suitable for drying and flour production [ 8 , 22 , 31 , 39 ]. Chestnuts can be consumed in their fresh state, raw, boiled, or roasted, or as a processed ingredient, such as chestnut flour, chestnut flakes, purée, yogurts, or candied chestnuts; see Figure 4 [ 8 , 31 , 39 , 108 ].…”

“…Thus, there is a long history of culture and tradition around chestnuts, especially those from Southern Europe [ 5 ]. In the Middle Ages, chestnut was used as the main ingredient in bread production [ 6 ], and in periods of food crisis with a scarcity of food resources, the chestnut was fundamental in the food supply [ 7 , 8 ], especially in the 18th century, which is said to have been the worst famine century in history [ 9 , 10 ].…”