Nutritional quality of chestnut (Castanea sativa Mill.) cultivars from Portugal

Comparative evaluation of physical and chemical properties, nutritional components and volatile substances of 24 chestnut varieties in Yanshan area

Chestnut (Ctanea mollissima Blume) is a nut with high nutritional value, yet studies on the quality of different chestnut varieties are limited. We evaluated 24 chestnut varieties from the Yanshan area by analyzing their physicochemical properties, nutritional components, mineral element content, and aroma profiles. A chestnut quality evaluation model was established by analyzing chestnut quality indicators. The study revealed significant differences in the quality of the chestnut varieties. Vitamin C content was highest in Qianxi Duanzhi at 33.37 mg/100 g. Zunhua Yanshanzaofeng had the highest Cu, Mg, and Ca element contents. The variety with the highest overall quality score was Chengde Kuancheng Yanshanzaofeng. Volatile components were analyzed using multivariate data analysis, which identified 11 key aroma compounds. These compounds can serve as characteristic markers for differentiating chestnut varieties and production regions. The results of the study will provide a theoretical basis and guidance for the consumption and processing of chestnuts.

A sustainable solution for aquaculture wastewater treatment: Evaluation of tannin-based and conventional coagulants

The global population faces increasing challenges in securing fresh water and food production. Aquaculture, a key source for obtaining protein, contributes significantly to environmental pollution, releasing suspended solids, organic matter, nitrogen, and phosphorus into water bodies. Some wastewater treatment methods can be expensive due to high equipment, energy, reagents, and maintenance costs, prompting the search for more sustainable alternatives. This study evaluates the performance of tannin-based coagulants from Castanea sativa shells (CS) for treating the recirculating water in an aquaculture plant. Two tannin-based coagulants, C1 and C2, were produced using ethanolamine (ETA) and NH4Cl, respectively. The efficiency in removing color, turbidity, organic matter, nitrogen, and phosphorus was compared to a commercial tannin-based coagulant (Tanfloc SG) and chemical ones (FeCl3 and Al2(SO4)3). Coagulant C2, at 10 mg L-1, removed 90 % of turbidity and 32 % of phosphorus, outperforming the Al-based coagulants (20 mg L-1). Moreover, CS-based coagulants reduced natural organic matter (NOM), expressed as UV absorbance at 254 nm, and dissolved organic carbon (DOC), though none significantly reduced the nitrogen levels. Toxicity tests indicated low bacterial inhibition, with C1 and C2 showing inhibition rates of 8-10 %. The sludge produced was rich in calcium (97-1500 mg g-1), magnesium (408-638 mg g-1), and potassium (347-894 mg g-1), making it suitable as a soil conditioner, though further research is necessary. Tannin-based coagulants, particularly from chestnut shells, offer a promising, sustainable solution for the post-treatment of the effluent from an aquaponics system on a fish farm while reducing organic sludge production.

Towards a better understanding of the structure-function relationship of chestnut starches

Chestnut starch is of increasing interest for applications in foods but has been studied to a much lesser extent than other food starches. Hence, the structure-function relationships of starches isolated from eight chestnut cultivars were examined. The starch granules were round, oval and conical in shape, with average particle size and amylose content ranging between 7.14 and 9.39 μm and 29.9 to 34.0 %, respectively. Chain length distributions showed larger differences between the starches in the A chains than in the B1 ∼ B3 chains. All chestnut starches exhibited a typical B-type crystalline pattern, with the relative crystallinity ranging from 34.1 to 40.6 %. Significant differences were also observed in short-range molecular order and in functional properties. Pearson correlation analyses showed that amylose content was positively correlated with peak and breakdown viscosities and negatively correlated with the rate of in vitro digestion of the starches. The short A chains were negatively and the B2 or B3 chains positively correlated with the peak and breakdown viscosities, but the opposite correlations were noted for the rate of in vitro digestion of the starches. This study contributes new insights into an understanding the structure-function relationships of chestnut starches and for their applications in foods.

Chitosan-hydroxypropyl methylcellulose and sodium alginate bilayer edible films for chestnut preservation

To address the challenge of preserving fresh chestnuts, chitosan (CS), hydroxypropyl methylcellulose (HPMC), nisin (N), and sodium alginate (SA) were utilized in the preparation of a bilayer edible film named CS-HPMC-N/SA, which was compared to the monolayer films CS-HPMC and CS-HPMC-N. In comparison to the CS-HPMC film, the CS-HPMC-N and CS-HPMC-N/SA films exhibited increased water vapor permeability (WVP), oxygen permeability, and thickness, while transparency, tensile strength (TS), and elongation at break (EAB) were reduced. The bilayer film CS-HPMC-N/SA showed higher WVP, transparency, thickness, and EAB, but lower TS than the monolayer film CS-HPMC-N. The chestnuts coated with CS-HPMC-N/SA showed lower respiratory intensity and decay rate compared to those coated with CS-HPMC and CS-HPMC-N. These results suggested that the bilayer film CS-HPMC-N/SA, containing nisin, has potential as an edible material for preserving fresh chestnuts.

Improvement of nutritional properties of regular and gluten-free cakes with composite flour

This study was carried out to develop regular and gluten-free cakes with the high nutritional and functional value from composite flours. Composite flour was prepared by blending of equal amounts of chestnut, lupine and pumpkin flour. Wheat flour (for regular cake) and corn starch: rice flour blend (for gluten-free cake) used in cake formulation were replaced with composite flour in ratios of 9, 18, 27 and 36%, respectively. Composite flour had a significant (p < 0.05) effect on all color parameters of the crust and crumb of regular and gluten-free cake samples. Cake weight and hardness values increased with the use of composite flour in regular and gluten-free cake samples, and higher weight and hardness values were determined in gluten-free cakes. High composite flour ratios (27-36%) resulted in the lowest cake volume in both cakes. The gluten-free cake had lower ash, protein, antioxidant activity and total phenolic content (TPC) compared to the regular cake. The composite flour usage increased the ash, protein, antioxidant activity, TPC, and mineral contents of both cake samples. When the nutritional, functional, technological and sensory properties of cakes were evaluated together, it was concluded that the use of 9% composite flour was the most appropriate ratio for both cake types.

Chestnut polysaccharide rescues the damaged spermatogenesis process of asthenozoospermia-model mice by upregulating the level of palmitic acid

Introduction

In recent years, the quality of male semen has been decreasing, and the number of male infertilities caused by asthenozoospermia is increasing year by year, and the diagnosis and treatment of patients with asthenozoospermia are gradually receiving the attention of the whole society. Due to the unknown etiology and complex pathogenesis, there is no specific treatment for asthenozoospermia. Our previous study found that the administration of chestnut polysaccharide could alter the intestinal microbiota and thus improve the testicular microenvironment, and rescue the impaired spermatogenesis process by enhancing the expression of reproduction-related genes, but its exact metabolome-related repairment mechanism of chestnut polysaccharide is still unclear.

Methods and results

In this study, we studied the blood metabolomic changes of busulfan-induced asthenozoospermia-model mice before and after oral administration of chestnut polysaccharide with the help of metabolome, and screened two key differential metabolites (hydrogen carbonate and palmitic acid) from the set of metabolomic changes; we then analyzed the correlation between several metabolites and between different metabolites and intestinal flora by correlation analysis, and found that palmitic acid in the blood serum of mice after oral administration of chestnut polysaccharide had different degrees of correlation with various metabolites, and palmitic acid level had a significant positive correlation with the abundance of Verrucomicrobia; finally, we verified the role of palmitic acid in rescuing the damaged spermatogenesis process by using asthenozoospermia-model mice, and screened the key target gene for palmitic acid to play the rescuing effect by integrating the analysis of multiple databases.

Discussion

In conclusion, this study found that chestnut polysaccharide rescued the damaged spermatogenesis in asthenozoospermia-model mice by upregulating palmitic acid level, which will provide theoretical basis and technical support for the use of chestnut polysaccharide in the treatment of asthenozoospermia.

Chemical and Bioactive Screening of Green Polyphenol-Rich Extracts from Chestnut By-Products: An Approach to Guide the Sustainable Production of High-Added Value Ingredients

Opportunities for the valorisation of agro-industrial residues of the chestnut (Castanea sativa Mill.) production chain have been fostered with the production of multifunctional polyphenol-rich extracts with the potential to be introduced as natural additives or active components in several products. Nonetheless, it is crucial to explore the feasibility of different extracts from the various by-products for these applications through the exhaustive study of their composition and bioactivities without losing sight of the sustainable character of the process. This work aimed at the screening of the phenolic compound composition and bioactivities of different green extracts of chestnut burs, shells and leaves, as the first step to establish their potential application as natural ingredients, primarily as food preservatives. To this end, maceration (MAC) as a conventional extraction method besides ultrasound and microwave-assisted extractions (UAE and MAE) was employed to obtain the extracts from chestnut by-products using water (W) and hydroethanolic solution (HE) as solvents. Phenolic compounds were analysed by HPLC-DAD-(ESI-)MS/MS; the antioxidant capacity was assessed by colourimetric assays, and the antimicrobial activity was evaluated against several strains of food-borne bacteria and fungi. The leaf extracts obtained by MAC-HE and UAE-HE presented the highest concentration of phenolic compounds (70.92 ± 2.72 and 53.97 ± 2.41 mg.g^-1 extract dw, respectively), whereas, for burs and shells, the highest recovery of total phenolic compounds was achieved by using UAE-HE and UAE-W (36.87 ± 1.09 and 23.03 ± 0.26 mg.g^-1 extract dw, respectively). Bis-HHDP-glucose isomers, chestanin and gallic acid were among the most abundant compounds. Bur extracts (MAC-HE and UAE-HE) generally presented the highest antioxidant capacity as measured by TBARS, while the best results in DPPH and reducing power assays were found for shell extracts (MAE-W and MAC-HE). Promising antibacterial activity was noticed for the aqueous extracts of burs, leaves and hydroethanolic extracts of shells, with emphasis on the MAE-W extract of burs that showed bactericidal activity against E. cloacae, P. aeruginosa and S. aureus (MBC 5 mg.mL^-1). Overall, it can be concluded that chestnut by-products, including burs, shells and leaves, are sources of polyphenolic compounds with significant antioxidant and antimicrobial activities. The choice of extraction method and solvent greatly influenced the composition and bioactivity of the extracts. These findings highlight the potential of chestnut by-products for the development of natural additives, particularly for food preservation, while also emphasizing the importance of sustainable utilization of agricultural waste materials. Further research is warranted to optimize extraction techniques and explore additional applications for these valuable bioactive compounds.

Sensory and physicochemical properties of biscuit produced from blends of whole wheat, soy okara and tigernut residue flours

Biscuits are popular ready to eat, cheap and convenient food products that are consumed globally. Supplementation of wheat flour with inexpensive staples from other cereals, legumes, roots and tubers will help in improving the nutritional quality of wheat products. Therefore, this study investigated the sensory and physicochemical properties of biscuits produced from blends of whole wheat, soy okara and tigernut residue flours. The sensory qualities of the twelve whole wheat, soy okara and tigernut residue flour biscuits at p < 0.05 ranged from 5.36 to 7.68 (color), 5.60-7.64 (appearance), 4.48-7.96 (mouthfeel), 4.28-7.76 (aroma), 3.96-8.32 (taste), 3.64-8.20 (crunchiness), 3.56-7.56 (crispiness), and 5.08-8.36 (overall acceptability). Physical, proximate and mineral analysis were carried out on the best five biscuit samples containing 100:0:0 (MVP), 60:20.98:19.02 (ISP), 50.75:39.25:10 (JAR), 53.79:22.57:23.64 (GEN) and 56.32:27.39:16.29 (XEC) whole wheat, soy okara and tigernut residue flours respectively. The physical analysis showed that diameter (38.13-38.17 mm), height (37.73-37.76 mm) and thickness (6.10-6.17 mm) were not significantly different, but the weight (7.30-7.73 g), spread ratio (5.73-6.10 mm) and breaking strength (600-643 g) significantly (p < 0.05) differed among the biscuit samples. The proximate composition of the biscuits ranged from; ash (1.70-1.90%), moisture (4.00-5.70%), fiber (7.00-11.30%), fat (16.20-17.30%), protein (6.50-12.00%), carbohydrate (56.94-59.20%) while mineral content ranged from; magnesium (122.00-134.00 mg/100 g), sodium (16.00-28.00 mg/100 g), calcium (12.00-24.00 mg/100 g), iron (2.30-3.50 mg/100 g) and phosphorus (100.00-121.00 mg/100 g). The study showed that substitution of wheat flour with soy okara and tigernut residue flour at a ratio of 60:20.98:19.02 yielded the most acceptable biscuits in all the sensory attributes assessed. This implies that biscuits produced from this composite blend contain sufficient amounts of protein, fat, fiber and carbohydrate. Hence, they can serve as relief for malnutrition.

Composition of Nuts and Their Potential Health Benefits-An Overview

The possibility that nut intake may defend human health is an interesting point of view and has been investigated worldwide. Consequently, nuts are commonly promoted as healthy. In recent decades, the number of investigations proposing a correlation between nut consumption and a decrease in the risk of key chronic diseases has continued to increase. Nuts are a source of intake of fiber, and dietary fiber is associated with a reduced occurrence of obesity and cardiovascular diseases. Nuts likewise provide minerals and vitamins to the diet and supply phytochemicals that function as antioxidant, anti-inflammatory, and phytoestrogens agents and other protective mechanisms. Therefore, the main goal of this overview is to summarize current information and to describe the utmost new investigation concerning the health benefits of certain nuts.

Improving chestnut physicochemical properties through fermentation - Development of chestnut Amazake

The increased awareness of population regarding the impact of consumption habits is leading to interest in new, innovative, diversified and health promoting foods. In this work, two new amazake fermented products were developed with chestnut (Castanea sativa Mill.), using rice or chestnut koji as source of glycolytic enzymes. The analysis of the amazakes evolution showed improvements in chestnuts physicochemical characteristics. The fermented products presented higher values of soluble protein, sugars, starches, antioxidant capacity, and similar values of ascorbic acid for chestnut koji amazake. The adhesiveness increased, which is related to the enhanced concentrations of sugars and starches. The evolution into less structured products was observed in the firmness followed by a consistent decrease of the viscoelastic moduli. The developed chestnut amazakes can represent a suitable alternative to traditional amazake, creating an opportunity for valorisation of chestnut industrial by-products, as new, tasty, and nutritive fermented products with potential functional characteristics.

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

The European chestnut (Castanea sativa Mill.), is an environmentally and economically important species in Europe, mainly for fruit production. The chestnut fruit is well-known for its nutritional properties, namely its high concentration of carbohydrates (starch) and its low-fat content, as well as being one of the few fruits that do not contain gluten. Due to its chemical and nutritional characteristics beneficial to health, the sweet chestnut is a food recommended at different levels. The biochemistry of the mouth and nose of a human being is very complex. However, understanding the different interactions between the biochemistry of our sensory organs and food helps us to comprehend certain concepts, such as flavor and how it is involved in the sensory evaluation of the chestnuts. For the selection of high-quality products, it is necessary to develop reliable methods both from a qualitative and sensory point of view, and chestnut is a fruit with unique sensory characteristics that can be used in various gastronomic dishes, from main courses to desserts.

Antioxidant Activity, Total Phenolic Content and Total Flavonoid Content in Sweet Chestnut (Castanea sativa Mill.) Cultivars Grown in Northwest Spain under Different Environmental Conditions

The sweet chestnut fruit has always had great importance in the southern European countries. Chestnut production is an important source of income and a crop of high environmental value thanks to its role in soil protection. It is also a good food with enormous potential for various aspects of health because of its nutritional qualities. The quality of sweet chestnuts is affected by various factors, such as climatic conditions and cultivation inputs. It is very important to recognize the impacts of climate on chestnut fruits, to improve our current understanding of climate-chestnut interconnections. The current study investigated and compared the antioxidant activity and the total phenolic and flavonoid contents of different cultivars of chestnuts grown in different geographic areas of northwest Spain. The results obtained with three antioxidant capability assays (DPPH, ABTS and FRAP assays) were highly correlated. All the samples had high antioxidant capacity and high total phenolic and total flavonoid contents, which depended both on cultivar and growth region. Ventura variety, harvested in the coldest environments, presented the highest values of antioxidant activity (IC50DPPH = 34.5 g/L), total phenolic content (131.84 mg equivalent of gallic acid/100 g FW) and total flavonoids (7.77 mg eq. catechin/100 g). The variations in the antioxidant capacity, total phenolic and total flavonoid contents of different cultivars, and their associations with climatic environmental factors, revealed the significant impacts of these factors on the synthesis of specialized metabolites and on the nutraceutical potential of chestnuts. The results can provide valuable information for selection of the cultivar and the cultivation conditions of the chestnut, in order to obtain chestnuts with high-quality bioactive characteristics.

Quality and Technological Properties of Flour with the Addition of Aesculus Hippocastanum and Castanea Sativa

The study of alternative food sources or ingredients that can partially replace or enrich today’s food is a perspective direction. The possibility of using horse chestnut (Aesculus hippocastanum) and chestnut (Castanea sativa) fruits in the baking industry as an admixture to wheat flour has been determined. The addition of flours from these fruits at a level of 10% increases the number of minerals in the flour mixture and also enriches the mixture in saponins, coumarins, and tannins. However, it is necessary to remove excess saponins from horse chestnut. The amylograph has shown that flour from horse chestnut fruit has optimal parameters for baking mixed bread. Farinograph tests showed that a 10% addition of ground horse chestnut to wheat flour had the best baking properties. Mixtures with 10 and 15% chestnut addition showed the best baking characteristic.

Sensory properties of Australian bunya nuts

Abstract

Bunya nuts are the seeds of Araucaria bidwillii, a conifer native to South‐East Queensland, Australia. They are one of the 19 species of Araucaria family found around the world, with the nuts from South America being the most commonly consumed. They are traditionally eaten boiled or roasted. This study aims to profile the sensory properties of bunya nuts with chestnut as a comparator. Since chestnuts do not come from a conifer tree, it is expected that there will be differences. Different methods of preparation are also expected to change the sensory attributes. Representative samples were collected from a variety of locations in South‐East Queensland, prepared and presented to a panel of 14 experienced tasters applying conventional sensory descriptive profiling.

Practical Application

There is an increase demand for local, sustainable, and natural foods. Bunya nuts are native to Australia and are part of the Araucaria family, which includes 19 species that can be found around the world. To the best of our knowledge there is no study characterizing Araucaria nuts in terms of sensory attributes. This study builds a lexicon for bunya nuts and compares to chestnuts. It also shows how different preparation methods affect its sensory attributes, as well as possible future uses in product development. The outcomes might provide information to support studies on Araucaria nuts in other countries.

Morpho-Agronomic and Biochemical Characterization of Accessions of Tiger Nut (Cyperus esculentus) Grown in the North Temperate Zone of China

Tiger nut (Cyperus esculentus L.) has recently attracted increasing interest from scientific and technological communities because of its potential for serving as additional source of food, oil, and feed. The present study reports morphology and biochemical characterization of 42 tiger nut accessions collected from China and other counties performed in the 2020 and 2021 growing seasons at Nongan, Jilin Province. Assessment of variability of 14 agronomic traits including plant height, maturation, leaf width, tilling number, color, size, and shape: 100-tuber weight showed a wide range of phenotypic variation. The color, size, and shape and maturation of the tubers, as well as the leaf width, were the most distinct characteristics describing variation among the accessions. Compositional analyses of major nutritional components of the tubers reveals that this crop could be a source of high-value proteins, fatty acids, and carbohydrates. Specifically, tiger nut tubers contained high levels of starch, oil, and sugars, and significant amounts of fiber, Ca, P, and Na. Furthermore, the tubers appeared to be a good source of proteins as they contain 16 amino acids, including the essential ones. Amino acid profiles were dominated by aspartic acid followed by glutamic acid, leucine, alanine, and arginine. Overall, these results demonstrated that tiger nut is well adapted to the temperature and light conditions in the north temperate zone of China, even with a shorter growth season. The tiger nut accessions collected here exhibited wide variations for agronomical and biochemical traits, suggesting potential for potential for breeding improvement by maximizing the fresh tuber and grass yield based on the optimal selection of genetic characteristics in climate and soil conditions of northern China.

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

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.

Phytochemical and Nutritional Profile Composition in Fruits of Different Sweet Chestnut (Castanea sativa Mill.) Cultivars Grown in Romania

Chestnut (Castanea sativa Mill.), a valuable fruit crop, is cultivated in small areas in Romania, mostly in the west, where the moderate continental climate has a slight Mediterranean influence. This work aims to investigate the bioactive characteristics (total polyphenols, total flavonoids and antioxidant activity), individual polyphenolic composition, phytochemical and nutritional HRMS screening profiles, sugar and mineral composition of six sweet chestnut cultivars, namely ‘Marsol’, ‘Maraval’, ‘Bournette’, ‘Précoce Migoule’ and ‘Marissard’ grown at Fruit Growing Research—Extension Station (SCDP) Vâlcea, in Northern Oltenia, Romania. Fruit samples were collected in two consecutive years, in order to study the impact of genetic variability between cultivars and the influence of the different climatic conditions corresponding to different cultivation years. Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) allow the discrimination between the sweet chestnut fruits harvested in different years and different sweet chestnut cultivars. Analytical investigations revealed that sweet chestnut cultivars grown in Romania show similar bioactive, phytochemical and nutritional composition to cultivars grown in the large European chestnut-producing countries, indicating the high adaptation potential of the chestnut in the temperate continental zone with small Mediterranean influences characteristic of the southwestern area of Romania.

Morphological and Chemical Variation of Wild Sweet Chestnut (Castanea sativa Mill.) Populations

Sweet chestnut (Castanea sativa Mill., Fagaceae) is one of the oldest cultivated tree species in the Mediterranean, providing multiple benefits, and, since it has edible seeds, it represents an interesting model species for the research of morphological and chemical variability. In this study, morphometric methods and chemical analyses were used to quantify the extent of differences in phenotypic and nutritional traits between eight natural populations of sweet chestnut from different environmental conditions, where different management types are applied, high-forest and coppice. The samples were collected from the Prealps in Italy to the western part of Bosnia and Herzegovina. In total, 31 nut and kernel morphometric and nutritional traits were studied on 160 trees, and various multivariate statistical analyses were used to study intra- and interpopulation variations. Both analyses, morphometric and chemical, revealed a similar pattern of diversity, with morphological and chemical variability not associated with geographic or environmental variables. In addition, we found significant correlations between morphometric and chemical data. High phenotypic variability was determined both among and within the studied populations, and all populations had a similar level of diversity. The results of the analysis of morphological and chemical diversity can have many practical applications for the management, production, and conservation of the sweet chestnut genetic resources for nut production.

Chestnut Cultivar Identification through the Data Fusion of Sensory Quality and FT-NIR Spectral Data

The world production of chestnuts has significantly grown in recent decades. Consumer attitudes, increasingly turned towards healthy foods, show a greater interest in chestnuts due to their health benefits. Consequently, it is important to develop reliable methods for the selection of high-quality products, both from a qualitative and sensory point of view. In this study, Castanea spp. fruits from Italy, namely Sweet chestnut cultivar and the Marrone cultivar, were evaluated by an official panel, and the responses for sensory attributes were used to verify the correlation to the near-infrared spectra. Data fusion strategies have been applied to take advantage of the synergistic effect of the information obtained from NIR and sensory analysis. Large nuts, easy pellicle removal, chestnut aroma, and aromatic intensity render Marrone cv fruits suitable for both the fresh market and candying, i.e., marron glacé. Whereas, sweet chestnut samples, due to their characteristics, have the potential to be used for secondary food products, such as jam, mash chestnut, and flour. The research lays the foundations for a superior data fusion approach for chestnut identification in terms of classification sensitivity and specificity, in which sensory and spectral approaches compensate each other's drawbacks, synergistically contributing to an excellent result.

Transcriptome sequencing and differential expression analysis of seed starch accumulation in Chinese chestnut Metaxenia

Background

Chestnut seeds are important kinds of edible nuts rich in starch and protein. The characteristics and nutrient contents of chestnut have been found to show obvious metaxenia effects in previous studies. To improve the understanding of the effect of metaxenia on chestnut starch and sucrose metabolism, this study used three varieties of chestnut, ‘Yongfeng 1’, ‘YongRen Zao’ and ‘Yimen 1’, as male parents to pollinate the female parent, ‘Yongfeng 1’, and investigated the mechanisms of starch and sucrose metabolism in three starch accumulation stages (70 (S1), 82 (S2), and 94 (S3) days after pollination, DAP) in chestnut seed kernels.

Result

Most carbohydrate metabolism genes were highly expressed in YFF (self-pollinated ‘Yongfeng 1’) in stage S2 and in YFR (‘Yongfeng 1’ × ‘Yongren Zao’) and YFM (‘Yongfeng 1’ × ‘Yimen 1’) in stage S3. In stage S3, hub genes encoding HSF_DNA-binding, ACT, Pkinase, and LIM proteins and four transcription factors were highly expressed, with YFF showing the highest expression, followed by YFR and YFM. In addition, transcriptome analysis of the kernels at 70, 82 and 94 DAP showed that the starch granule-bound starch synthase (EC 2.4.1.242) and ADP-glucose pyrophosphorylase (EC 2.7 .7.27) genes were actively expressed at 94 DAF. Chestnut seeds regulate the accumulation of soluble sugars, reducing sugars and starch by controlling glycosyl transferase and hydrolysis activity during development.

Conclusion

These results and resources have important guiding significance for further research on starch and sucrose metabolism and other types of metabolism related to chestnut metaxenia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-07923-5.

Effect of Coconut and Chestnut Flour Supplementations on Texture, Nutritional and Sensory Properties of Baked Wheat Based Bread

Wheat bread, produced by the single-phase method, is a common food consumed all over the world. Due to changes in lifestyle and nutritional trends, alternative raw materials are sought to increase the nutritional value and improve the taste of daily consumed products. Additionally, customers seek a wide variety of foods, especially when it comes to basic foods. Nuts, such as coconuts or chestnuts, might provide an attractive flavour with benefits to the nutritional quality. In this study, the effect of substituting wheat flour with coconut or chestnut flour (flour contribution level: 5, 10, 15, 30, 50% w/w), was evaluated in terms of the breads specific volume, texture, colour, nutritional composition, and dietary fibre fraction contents. Moreover, a sensory evaluation was conducted to assess potential consumer acceptance. Based on the consumer's perception, the overall acceptance of bread with 15% w/w of coconut and chestnut flour was in privilege compared to the control sample. As a result, taking all of the tested parameters into account, the breads with 5, 10, and 15% supplementation of chestnut or coconut flour were still of good quality compared to the wheat bread and their fibre content was significantly higher.

Drying Kinetics and Quality of Whole, Halved, and Pulverized Tiger Nut Tubers (Cyperus esculentus)

The objective of this study was to provide the optimum drying conditions to produce high-quality dried tiger nuts using hot-air drying. For this, we evaluated the effect of the whole, halved, and pulverized tiger nuts and air temperature (50 to 70°C) on the drying kinetics and quality of tiger nuts. The drying process generally followed a constant rate in the first 3 hours and a falling regime. We found the optimum drying conditions for tiger nuts to be crushed before convective hot-air drying at a temperature of 70°C. At this optimum condition, the predicted drying time, vitamin C content, reducing sugars, browning, brightness, redness, and yellowness was 780 min, 22.9 mg/100 mg dry weight, 157.01 mg/100 g dry weight, 0.21 Abs unit, 56.97, 1.6, and 17.0, respectively. The tiger nut's reducing sugars increased from the 130.8 mg/100 dry weight in the raw tiger nuts to between 133.11 and 158.18 mg/100 dry weight after drying. The vitamin C degradation rate was highest in the uncut tiger nuts (32-35%) while in the halved and the pulverized samples, it was between 12 and 17%. The crushed samples' effective moisture removal increased between 5.6- and 6.75-fold at the different air temperatures than that of the intact tiger nuts. The activation energy was 18.17 kJ/mol for the unbroken, 14.78 kJ/mol for the halved, and 26.61 kJ/mol for the pulverized tiger nut samples. The model MR = 0.997 exp(−0.02t^1.266) + 0.0000056t was the most suitable thin-layer drying model among the models examined for convective hot-air drying of tiger nuts. It is advisable to crush tiger nut before hot-air drying to produce better-quality flour for making milk beverages, cakes, biscuits, bread, porridge, and tiger nut-based breakfast cereals.

Phenotypic Characterization of Tiger Nuts (Cyperus esculentus L.) from Major Growing Areas in Ghana

Tigernut (Cyperus esculentus Lativum) is an important but understudied and underutilized crop in Ghana. The tubers are highly appreciated for their health benefits and nutritive value. To contribute to the conservation process of tiger nut and identify elite genotypes, this study was conducted to assess phenotypic variability in tiger nut genotypes in Ghana. Sixty-four (64) genotypes were collected from major tiger nut growing areas in Ghana. The genotypes were field-grown and characterized based on phenotypic and yield traits. Similarity coefficient (Bray-Curtis) was between 0.82 and 0.98, indicating low variability in both qualitative and quantitative characters. The cophenetic correlation coefficient was 0.64. The genotypes were mainly brown with only a few black (6) tubers from the central region. Materials collected from parts of the eastern region (Aduamoah) generally recorded the highest tuber weight. Tuber weight depended on plant height and number of tillers. There were high tillering genetic materials among the genotypes. Tubers were categorised as oval (10), ovoid (33), or oblong (15). The genotypes clustered into two groups based on shoot and tuber characteristics, rather than on geographical origin. The low genetic diversity among the genotypes suggested either the possible existence of a network among tiger nut farmers in Ghana in circulating the planting material or some form of seed sorting for uniform and homogenous planting materials has been carried out over the years. Our results point to the imperativeness to expand the genetic base of the tiger nuts to facilitate its improvement in Ghana.

Fluoride-induced testicular degeneration and sperm quality deteriorations: Salutary role of Cyperus esculentus tubers (tiger nut) extract in animal model

OBJECTIVE

Chronic exposure to fluoride causes tissue damage induced by oxidative imbalance, Cyperus esculentus (CE) possess anti-inflammatory and immunostimulatory properties. This study focused on Salutary role of Cyperus esculentus in sodium fluoride (NaF) induced testicular degeneration and sperm quality deteriorations.

METHODS

Sexually mature male Sprague-Dawley rats were randomly divided into four groups (n=6). Animals in control group received 2 mls of normal saline per day; CE group received 500mg/kg bw of CE; NaF group received 5mg/kg bw of NaF; NaF+CE group received 500mg/kg bw of CE (for 14 days pre-treatment) and NaF co-treatment till 56 days via gastric gavage. Parameters tested include: testicular histology, sperm parameters, sex hormone, fertility test, malondialdehyde (MDA), superoxide dismutase (SOD), reduced glutathione, glutathione peroxidase (GPX), catalase (CAT), testicular fluoride and testicular cholesterol.

RESULTS

Sodium fluoride significantly (p<.05) decrease testicular antioxidant (SOD, CAT, GSH and GPx), sperm quality, hormone profiles (TT, FSH, LH, estrogen levels), testicular cholesterol, morphometric parameters, Johnsen's Score and number of implantations in female rats with corresponding (p<.05) increase in oxidative stress makers and abnormal sperm morphology. Also depleted seminiferous epithelium and degenerate spermatogenic cells. Pretreatment with 500mg/kg bw of CE lowered NaF toxicity by significantly reducing the lipid peroxidation products, fluoride accumulation in the testis, histopathological changes of the testes and spermatozoa abnormalities and reverted observed NaF-induced inhibition in antioxidant parameters and weight of accessory sex organs.

CONCLUSIONS

Cyperus esculentus attenuated NaF-induced testicular injuries and protected the seminiferous epithelium, reduced oxidative stress and promoted spermatogenesis.

Content of Phenolic Compounds and Antioxidant Activity of New Gluten-Free Pasta with the Addition of Chestnut Flour

Chestnut fruit abounds in carbohydrates, proteins, unsaturated fatty acids, fiber, polyphenolic compounds, as well as vitamins and micronutrients, that are behind the health-promoting properties of this plant. The purpose of the discussed research was to obtain innovative gluten-free pasta from rice and field bean flour enriched with a various addition of chestnut flour. Regarding the studied pasta, the following were determined: the content of free phenolic acids, total polyphenols, and antioxidant properties. Chromatographic analysis (HPLC-ESI-MS/MS (high-performance liquid chromatography-electrospray ionization tandem mass spectrometry)) revealed a wide variety of phenolic acids. In a sample with 20% and higher content of chestnut flour, as many as 13 acids were detected. Isoferulic acid prevailed. The total content of free phenolic acids and total polyphenols increased along with the increasing chestnut content. Moreover, in most cases, the content of individual acids increased with the addition of chestnut flour. Besides, the antioxidant activity was positively correlated with the addition of chestnut fruit flour, the content of free phenolic acids, and total polyphenols. Our research has demonstrated that our innovative gluten-free pasta, with the addition of chestnut flour, has a potential to be a source of polyphenolic compounds, including free phenolic acids, that are valuable for human health.

UAV-Based Automatic Detection and Monitoring of Chestnut Trees

Unmanned aerial vehicles have become a popular remote sensing platform for agricultural applications, with an emphasis on crop monitoring. Although there are several methods to detect vegetation through aerial imagery, these remain dependent of manual extraction of vegetation parameters. This article presents an automatic method that allows for individual tree detection and multi-temporal analysis, which is crucial in the detection of missing and new trees and monitoring their health conditions over time. The proposed method is based on the computation of vegetation indices (VIs), while using visible (RGB) and near-infrared (NIR) domain combination bands combined with the canopy height model. An overall segmentation accuracy above 95% was reached, even when RGB-based VIs were used. The proposed method is divided in three major steps: (1) segmentation and first clustering; (2) cluster isolation; and (3) feature extraction. This approach was applied to several chestnut plantations and some parameters—such as the number of trees present in a plantation (accuracy above 97%), the canopy coverage (93% to 99% accuracy), the tree height (RMSE of 0.33 m and R2 = 0.86), and the crown diameter (RMSE of 0.44 m and R2 = 0.96)—were automatically extracted. Therefore, by enabling the substitution of time-consuming and costly field campaigns, the proposed method represents a good contribution in managing chestnut plantations in a quicker and more sustainable way.

Chestnut Drying Is Critical in Determining Aspergillus flavus Growth and Aflatoxin Contamination

Chestnut drying is used to prevent postharvest losses and microorganism contamination during storage. Several studies reported the contamination by aflatoxins (AFs) produced by Aspergillus spp. in chestnuts. The effect of drying temperatures (from 30 to 50 °C) was evaluated on the growth of A. flavus and the production of aflatoxins in chestnuts. The influence of the treatment on the proximate composition, the total phenol content and antioxidant activity of chestnuts was considered. Fungal colonization was observed on the nuts dried at 30, 35, and 40 °C; the incidence was lower at 40 °C. The highest concentrations of AFB₁ and AFB₂ were produced at 40 °C. No aflatoxins were detected at 45 or 50 °C. At 40 °C A. flavus was under suboptimal conditions for growth (a_w 0.78), but the fungus was able to synthesize aflatoxins. As the temperatures applied increased, the total phenol content increased, while the antioxidant activity decreased. A drying treatment at 45 °C for seven days (a_w 0.64) could be a promising method to effectively control both the growth of aflatoxigenic fungi and the production of aflatoxins. This study provides preliminary data useful to improve the current drying conditions used in chestnut mills, to reduce both fungal growth and aflatoxin production.

Effects of drying methods on the nutritional aspects, flavor, and processing properties of Chinese chestnuts

To select a suitable drying process for using chestnut products in the food industry, this study investigated the effect of five drying methods, including natural drying, microwave drying (MD), hot air drying (HAD), freeze-vacuum drying (FVD) and microwave-vacuum drying (MVD) on the nutritional composition, flavor, and functional properties of dried chestnuts. The results indicated that the nutritional aspects and functional properties of chestnuts were enhanced by the freeze-drying process compared with the other four drying methods. The quality of the chestnuts dried using the MVD was second to the FVD. The hot-air dried products were quite similar to the naturally dried samples in terms of their functional component content and processability. In terms of the produce texture, the HAD was found to be the best. In total, 45 flavor components were identified in the samples, which comprised the following: 5 aldehydes, 4 alcohols, 4 esters, 8 terpenes, 16 hydrocarbons and, 8 others substances. The highest relative content of the ingredients in microwave-vacuum dried samples was pyrazine and 3-ethyl-2, 5-dimethyl. In the samples treated using the other four drying methods, benzyl alcohol was the ingredient with the highest concentration. Considering the fast drying rate, low energy consumption, and improved quality of chestnut products, MVD is the most suitable dehydration method for commercial production of Chinese chestnuts.

Amino acid composition and nutritional value evaluation of Chinese chestnut (Castanea mollissima Blume) and its protein subunit

The amino acid composition, nutritional value and proteins subunit of chestnuts (Castanea mollissima Blume) from three regions of China (Henan, Hunan, and Guangdong) were investigated. Experimental results showed that the albumin fraction dominated the chestnut protein composition, but globulin and prolamin were nondetectable. All the Chinese chestnut proteins had a nutritionally balanced amino acid composition. Their amino acid score (AAS) could reach the FAO/WHO (2013) requirement for essential amino acids for older children, adolescents and adults. Leucine was the first limiting amino acid for all the Chinese chestnut protein isolates and digestible indispensable amino acid scores (DIAAS) were more than 90 (Leu). The sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) spectra showed that different Chinese chestnut protein isolates had almost the same band components, which were mainly comprised of seven polypeptide segments with the molecular weights of (91-93) kDa, (70-72) kDa, (53-55) kDa, 37 kDa, (27-33) kDa, 20 kDa and (5-15) kDa. The amino acid compositions and the abundance of low molecular weight proteins indicated that Chinese chestnut could be utilized as a good source of plant protein for human nutrition.