A meta‐analysis of the effects of ultrasonic pretreatment on the characteristics of dried fruits and vegetables
Parameter selection in ultrasonic pretreatment is closely related to the quality of dried fruits and vegetables, so it is essential to investigate the impact of various parameters of ultrasonic pretreatment on the product quality. In this paper, data from 67 relevant literatures were collected to evaluate the effects of ultrasonic pretreatment on dried fruits and vegetables through meta-analysis. Overall, the findings indicated that ultrasonic pretreatment could shorten drying time, reduce hardness and improve color appearance of dried products. Subgroup analysis showed that high power ultrasound (P ≥ 300 W) could increase total phenol content and antioxidant activity of dried fruits and vegetables. Additionally, applying short-duration ultrasound (t < 15 min) increased antioxidant activity, while medium-duration ultrasound (15 min < t < 30 min) simultaneously enhanced flavonoid content and antioxidant activity. In summary, the application of ultrasonic pretreatment has a positive impact on processing high quality dried fruits and vegetables and obtains better-quality products in a shorter time compared to direct drying technology. https://doi.org/10.1111/jfpe.14689
Investigation of antioxidant edible coating and modified atmosphere packaging for enhancing storability of hazelnut kernels
This study investigated the effects of antioxidant edible coating and modified atmosphere packaging for improving storability of dried hazelnut kernels by delaying lipid oxidation and color degradation. Hazelnut kernels were coated with different coating matrix (methylcellulose and chitosan) that contain different antioxidant substances (DL-α-tocopherol acetate, cinnamon essential oil, rosemary essential oil and hazelnut oil) and subjected to an accelerated storage condition at 35 °C for 270 days. Hazelnut kernels were also packed under modified atmosphere (MAP) with 100 % N2 in mylar bags and stored at 35 °C for 180 days. Lipid oxidation (free fatty acids, K232 and K270, peroxide values) and color (browning index) were measured for investigating quality changes during the storage. The free fatty acids of kernels from two packaging experiments remained stable during storage. K232 value of MAP kernels was significantly lower (2.20) than that of control (2.90) at the end of the storage, showing delayed production of conjugated dienes. The chitosan based edible coating with encapsulated cinnamon essential oil and oleic acid (CH/ECO/OA) resulted in significantly (P < 0.05) lower PV values (0.53 meq/kg oil), and all the coated samples had the positive effect on reducing browning index with 12–25 compared with control. K270 (0.04–0.18) remained relatively low throughout the long-term storage. As a result, modified atmosphere packaging performed better than edible coatings. This study demonstrated the importance of implicating proper postharvest technology for reducing lipid oxidation and quality deteriorations of hazelnut kernels during prolonged storage. https://doi.org/10.1016/j.jafr.2024.101246
Powdery mildew caused by Erysiphe corylacearum: An emerging problem on hazelnut in Italy
Erysiphe corylacearum has recently been reported in northern Italy (Piedmont) and other European countries as the causal agent of a new emerging powdery mildew on hazelnut. This disease is much more dangerous than the common hazelnut powdery mildew caused by Phyllactinia guttata as it significantly reduces yield and quality of hazelnuts. This study aimed to perform morphological and molecular characterization of the fungal isolates from powdery mildew-infected plants in the Piedmont Italian region. Additionally, genetic diversity studies and pathogenicity tests were conducted. Thirty-six fungal isolates originating from symptomatic hazelnut plants exhibiting specific powdery mildew symptoms on the superior leaf side were identified morphologically as E. corylacearum. Single- and multilocus sequence typing of five loci (ITS, rpb2, CaM, GAPDH and GS) assigned all isolates as E. corylacearum. Multilocus and GAPDH phylogenetic studies resulted in the most efficient characterization of E. corylacearum. Studied fungal isolates were able to cause new emerging powdery mildew disease by fulfilling Koch's postulates. The emergence of powdery mildew disease in Italy revealed the E. corylacearum subgrouping, population expansion, and high nucleotide similarity with other recently identified E. corylacearum hazelnut isolates. To contain this harmful disease and inhibit the fungus spread into new geographical zones, it will be necessary to implement more rigorous monitoring in neighboring hazelnut plantations near infected hazelnuts, use sustainable fungicides and search for new biocontrol agents. https://doi.org/10.1371/journal.pone.0301941
Exploring the Untapped Potential of Pine Nut Skin By-Products: A Holistic Characterization and Recycling Approach
The increasing population, food demand, waste management concerns, and the search for sustainable alternatives to plastic polymers have led researchers to explore the potential of waste materials. This study focused on a waste of pine nut processing referred to in this paper as pine nut skin. For the first time, its nutritional profile, potential bioactive peptide, contaminants, and morphological structure were assessed. Pine nut skin was composed mainly of carbohydrates (56.2%) and fiber (27.5%). The fat (9.8%) was about 45%, 35%, and 20% saturated, monounsaturated, and polyunsaturated fatty acid, respectively, and Omega-9,-6, and -3 were detected. Notably, oleic acid, known for its health benefits, was found in significant quantities, resembling its presence in pine nut oil. The presence of bioactive compounds such as eicosapentaenoic acid (EPA) and phytosterols further adds to its nutritional value. Some essential elements were reported, whereas most of the contaminants such as heavy metals, polycyclic aromatic hydrocarbons, rare earth elements, and pesticides were below the limit of quantification. Furthermore, the in silico analysis showed the occurrence of potential precursor peptides of bioactive compounds, indicating health-promoting attributes. Lastly, the morphological structural characterization of the pine nut skin was followed by Fourier Transform Infrared and solid-state NMR spectroscopy to identify the major components, such as lignin, cellulose, and hemicellulose. The thermostability of the pine nut skin was monitored via thermogravimetric analysis, and the surface of the integument was analyzed via scanning electron microscopy and volumetric nitrogen adsorption. This information provides a more comprehensive view of the potential uses of pine nut skin as a filler material for biocomposite materials. A full characterization of the by-products of the food chain is essential for their more appropriate reuse. https://doi.org/10.3390/foods13071044
Effect of Pretreatment and Drying on the Nutritional and Functional Quality of Raisins Produced with Seedless Purple Grapes
Raisins, known for their delicious taste and high nutritional value, are among the most widely consumed dried fruits globally. The natural waxy layer on the surface of grapes impedes water migration, making pretreatment necessary before drying. This study evaluated the effects of various pretreatment methods on the nutritional and functional quality of seedless purple raisins. By using non-pretreated dry seedless purple raisins as a control, the impact of physical and chemical pretreatment methods on the nutritional and functional qualities of seedless purple raisins was assessed through the analysis of nutrient content, phenolic compounds, and antioxidant activity. Our results demonstrate that physical pretreatment significantly increases the levels of vitamin C, fructose, glucose, total acid, total phenolics, total flavonoids, total anthocyanins, and antioxidant activity compared to chemical pretreatment and the control group. The correlation analysis revealed that phenolic substances were closely linked to antioxidant capacity. Additionally, phenolic compounds, including resveratrol, ferulic acid, chlorogenic acid, ethyl coumarate, and cinnamic acid, were more abundant following physical pretreatment. The OPLS-DA model effectively differentiated the three groups of processed samples, showing that different pretreatments significantly affect the nutritional and functional quality of seedless purple raisins. These findings suggest that physical pretreatment offers considerable potential for improving the drying quality of seedless purple raisins. https://doi.org/10.3390/foods13081138
A Healthy Brazil Nut Beverage with Opuntia stricta var. dillenii Green Extract: Beverage Stability and Changes in Bioactives and Antioxidant Activity during Cold Storage
Plant-based beverages are one of the foods that currently arouse a lot of interest in the population due to their composition with compounds beneficial to health in addition to their being used as milk substitutes for people who suffer from food disorders. Also, their fortification with different nutrients or healthy ingredients with the aim of improving plant-based health potential is actually gaining importance in the food industry. For this reason, the aim of the present investigation was the preparation of a healthy Brazil nut beverage enriched with Opuntia stricta var. dillenii pulp green extracts (ODPs), in order to produce a healthy plant-based beverage with improved nutritional characteristics. The microstructural characterization of the Brazil nut beverage, its stability during cold storage for up to 24 days at 5 °C, the composition of bioactive compounds provided via ODP extract (betalains and phenolic compounds), and their antioxidant activity were evaluated in this study. Green ODP extracts (0.5 and 1 g/100 g beverage) were added to a standardized Brazil nut beverage (reduced fat beverage). The characterization of the bioactive composition (betalains and phenolic compounds) of the elaborated beverage was achieved via HPLC (UV-vis and MS-QT of detection), and the antioxidant activity measurements via ORAC were also carried out. Optical microscopy, particle size, and Z potential analysis was conducted to characterize the structure of the Brazil nut beverages as food emulsions in which ODP extract was added. Most of the bioactive compounds from the green ODP extract added to the beverages showed good retention and remained stable throughout the 24 days of storage at 7 °C, with encapsulation efficiencies ranging from 98.34% to 92.35% for betalains and from 93.67% and 81.20% for phenolic compounds. According to the results of this study, Brazil nut beverage seems to be a healthy and efficient food emulsion system to encapsulate ODP extract rich in betalains and phenolic compounds, with high antioxidant activity, making possible the development of a Brazil nut beverage with improved health potential. https://doi.org/10.3390/foods13081237
Development and characterization of gelatin-based biodegradable films incorporated with pistachio shell hemicellulose
This study aimed to incorporate pistachio shell hemicellulose into a film of gelatin and glycerol for the production of biodegradable films. The gelatin and glycerol are chosen because of their functional properties, which make it extensively used in food industry. The film composition was defined after a statistical optimization by central composite face-centered design and response surface methodology. The hemicellulose/gelatin ratio of 35.93% and the glycerol ratio of 18.02% were the optimum conditions to obtain lower film water solubility, higher tensile strength, and elongation at break values. The physical, structural, mechanical, and barrier properties of the developed hemicellulose-gelatin film were analyzed and compared with those of the gelatin film. Tensile strength and film water solubility values were reduced significantly with hemicellulose incorporation from 20.41 to 16.64 MPa and 49.57 to 39.21%, respectively, while EB was enhanced by 4.34 times. In addition, hemicellulose incorporation enhanced the water vapor permeability and the film degradation in the soil. The films were also examined by Fourier transform infrared spectroscopy and differential scanning calorimetry. The novelty of this study is to use pistcahio shell hemicellulose in the production of an edible film for the first time.
https://doi.org/10.1007/s13197-024-05968-4
Formulation of a probiotic product using Almond gum
Background: The application of probiotics in food has expanded significantly, yet its viability remains a challenge. In response to this issue, this study explores a unique approach. Almond gum, a natural extract from Prunus dulcis, is utilized as the primary carrier matrix for a novel probiotic product featuring Saccharomyces boulardii, a probiotic yeast. Methods: This study involves the entrapment of S. boulardii in almond gum through centrifugation (5 min at 1300 × g) and subsequent 24 h drying at 50 °C. Sensory evaluation and other investigations were conducted at different pH levels to assess viability and performance. Results: Post-drying entrapment efficiency was 83.85%, underscoring the benefits of choosing almond gum as a carrier matrix. Promising results were observed from viability testing conducted in gastric juice (pH 1.2) and in simulated intestinal fluid (pH 6.8). Matrix stability was assessed by measuring cfu ml-1 following 7 days' storage at different temperatures, complemented by sensory analysis. Conclusion: Almond gum is a promising carrier matrix for probiotic products. Its high entrapment efficiency and its viability under challenging pH conditions demonstrate its efficacy. It is rich in carbohydrates and serves a dual purpose by acting as a prebiotic source, as confirmed through ultraviolet-visible (UV-visible) analysis. The study underscores the potential of this novel approach, providing insights into responses to viability challenges in probiotic food products. © 2024 Society of Chemical Industry.
https://doi.org/10.1002/jsfa.13301
Macadamia oil-based oleogels as cocoa butter alternatives: Physical properties, oxidative stability, lipolysis, and application
In this study, macadamia oil-based oleogels were prepared using monoglyceride stearate (MG) as a gelator with a low critical gelation concentration (3.0 wt%). The physical properties of the oleogels were evaluated by polarized light microscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, texture and rheological analysis. And the lipid digestion and oxidative stability of the macadamia oil were determined by pH titration and accelerated oxidation test, respectively. The results showed that the hardness, oil binding capacity, and thermal stability of the oleogels increased with increasing MG concentration, which was attributed to the formation of a network of MG crystals held together by van der Waals interactions and hydrogen bonds. Rheological analysis indicated that all the oleogels exhibited a thermally reversible solid-to-liquid transition and viscoelastic behavior at ambient temperatures. Moreover, the formation of oleogels increased fatty acid release during in vitro lipid digestion and improved the oxidative stability of the macadamia oil. In addition, the potential application of these oleogels as replacements for saturated fats in foods was demonstrated by creating a chocolate product where the cocoa butter was replaced with macadamia oil-based oleogels with a high degree of unsaturation. These results can provide guidance for the preparation of macadamia oil-based oleogels, which may increase their application in foods.
https://doi.org/10.1016/j.foodres.2023.113098
Quality evaluation of fresh pistachios (Pistacia vera L.) cultivars coated with chitosan/TiO2 nanocomposite
Fresh pistachios are rich in dietary fiber, minerals and unsaturated fatty acids, but they have a short shelf life. This investigation examined the effect of pre-harvest foliar application with chitosan (500 and 1000 mg. L-1), nano-chitosan (250 and 500 mg. L-1), and chitosan/TiO2 nanocomposite (250 and 500 mg. L-1) coating films on the postharvest physiology and storage of fresh pistachios (Pistacia vera cvs. Akbari and Ahmad Aghaei) cultivar during storage at 4 ± 0.5 °C. It was found that, fresh pistachios' shelf life could by increased by up to 30 days by the use of chitosan/TiO2 nanocomposite coating for foliar application. The decay index of the composite coated fruits was 4-6 % lower than that of the control group, and after 50-60 days the bacterial contamination appeared in cultivars; respectively. The nanocomposite treatments reduced the fruits weight between 30 and 40 %, which was 15 % higher that of than uncoated fruits. The pre-harvest application of chitosan/TiO2 coating reduced microbial contamination, weight loss, phenylalanine ammonialyase (PAL) activity and saturated fatty acids, and increased unsaturated fatty acids, antioxidant properties, sensory properties, essential minerals, superoxide dismutase (SOD), quality indicators and shelf life. These results demonstrated that the chitosan/TiO2 (250 and 500 mg. L-1) coating film effectively preserved the nutrient composition, sensory quality, nutritional value, antioxidant capacity and shelf life of fresh pistachio.
https://doi.org/10.1016/j.ijbiomac.2023.129055