Production and characterization of freeze-dried banana slices pretreated with ascorbic acid and quince seed mucilage: Physical and functional properties

Freeze-Dried Banana Slices Carrying Probiotic Bacteria

Findings on diet-health relationships have induced many people to adopt healthier diets, including the substitution of energy-dense snacks with healthier items, e.g., those containing probiotic microorganisms. The aim of this research was to compare two methods to produce probiotic freeze-dried banana slices-one of them consisting of impregnating slices with a suspension of probiotic Bacillus coagulans, the other based on coating the slices with a starch dispersion containing the bacteria. Both processes resulted in viable cell counts above 7 log ufc.g^-1, although the presence of the starch coating prevented a significant loss in viability during freeze-drying. The coated slices were less crispy than the impregnated ones, according to the shear force test results. However, the sensory panel (with more than 100 panelists) did not perceive significant texture differences. Both methods presented good results in terms of probiotic cell viability and sensory acceptability (the coated slices being significantly more accepted than the non-probiotic control slices).

Effects of thermal treatments on the characterisation of microencapsulated chlorophyll extract of Caulerpa racemosa

Caulerpa racemosa is a macroalga that has a green pigment, that is, chlorophyll. Chlorophyll is highly sensitive to damage during heat processing. In the present work, C. racemosa chlorophyll extract was microencapsulated with fish gelatine and Arabic gum coatings, using a freeze-drying technique, to protect against heat damage. The microcapsules were subjected to high temperatures (120, 140, and 160°C) for 5 h. The protective effect of microcapsules on chlorophyll stability was assessed by measuring chlorophylls a and b degradation, total phenolic content, antioxidant activity, functional group analysis, colour, particle size, and morphology via scanning electron microscopy. Chlorophyll b significantly decreased by 87.78% in comparison with chlorophyll a (61.49%) during heating; the characteristic green colour of chlorophyll changed to brownish-green following heat exposure. However, chlorophyll was still present in the microcapsules as detected by the presence of the functional group C=O bond at 1600 nm wavelength. The heat treatment did not affect microcapsule particle size and morphology. Particle size distribution ranged from 91.58 to 112.51 µm, and the microcapsule was flake-shaped. The activation energy of chlorophyll a was 19336.96 kJ/mol·K; this was higher than that of chlorophyll b, which was 1780.53 kJ/mol·K. Based on the results, microcapsules produced using fish gelatine and Arabic gum as coating materials were able to protect chlorophyll in C. racemosa extract from heat damage.

Structural characterization of a new high molecular weight polysaccharide from jujube fruit

From Ziziphus Jujuba cv. Muzao fruit, a new polysaccharide (PZMP3-1) with high molecular weight was isolated. Constructional characterization revealed that PZMP3-1 comprized 2.56 rhamnose, 7.70 arabinoses, 3.73 galactose, and 6.73 galactose, and it has a 241 kDa average molecular weight. The principal structural components of PZMP3-1 were 1,2,4 and 1,4-linked GalpA, 1,4-linked Galp, 1,3 and 1,5-linked Araf, and 1-linked Rhap based on methylation and nuclear magnetic resonance spectroscopy (NMR) analyses. X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR), atomic force microscopy (AFM), and scanning electron microscopy (SEM) structural analysis of PZMP3-1 revealed a tangled and branching pattern. Overall, these structural results suggested that PZMP3-1 could have unique bioactivities and be widely used in nutritional supplements.

Partial substitution of sugar by honey in a pumpkin-based jam: Impact on physicochemical, microbiological quality and sensory attributes during refrigerated storage

The current study aimed to monitor the physicochemical, microbiological quality and sensory profile of pumpkin jam enriched with different proportions of honey, for an interval of 20 days during two months storage period. For that purpose, five jam samples were prepared; the first sample (A) is a control jam without addition of honey, the other four formulations B, C, D and E were prepared by replacing the granulated sugar with honey in different proportions of 5, 10, 15 and 20%, respectively. A decrease was observed in pH from 4.43 to 4.28, °Brix from 45.7 to 42.30%, except the sample C (fortified with 10% of honey) which showed Brix stability during storage; an increase in moisture content from 35.40 to 35.91%, titratable acidity from 1.163 to 1.179% was noted during evaluation. Microbiological examinations indicate that jams were microbiologically stable according to standards in force as all the count of the germs sought revealed lower loads and the total absence of pathogenic germs up to 60 days of refrigerated storage. The appreciation of jams by tasters tended to decrease towards the end of storage, where, on a hedonic scale of 5 points, the scores exhibited values between 1.3 and 3.6.

Effects of sucrose and sodium chloride pretreatments on cassava and plantain chips fried in CLA-enriched soybean oil: an analysis of acrylamide content, microstructure, and other physical properties

The purpose of this research was to evaluate the effect of soaking plantain and cassava chips in sucrose or sodium chloride (NaCl) on their physical properties and acrylamide content after frying in Conjugated Linoleic Acid (CLA)-enriched soybean oil. Plantain and cassava were cut into 1 mm thick slices and soaked for 20 min in a solution of 30% sucrose or 3% NaCl at 40 °C, separately. Soaking in sucrose and NaCl had no significant effect (p < 0.05) on water loss, porosity, hardness, or microstructure. The acrylamide content ranged from 634 to 3177 µg/kg. The use of CLA-enriched oil had no significant effect (p < 0.05) on the physical characteristics evaluated in this study. Frying reduced the CLA content in the chips from an initial 31.8% in the oil to 22.25 and 21.69% in plantain and cassava chips, respectively.

Antioxidative capacity of fresh kombucha cheese fortified with sage herbal dust and its preparations

Recent studies have intensively investigated the possibility of kombucha application as non-conventional starter culture in manufacture of various fermented dairy products. Furthermore, natural extracts from medicinal and aromatic plants contain different biologically active components which often have antioxidant properties. Based on the stated above, the aim of this research was to investigate the possibility of kombucha inoculum application as a new starter culture in fresh cheese technology, as well as to investigate effects of sage (Salvia officinalis) herbal dust (by-product from filter tea factory), its essential oil and supercritical fluid extract on antioxidative activity and sensory characteristics of produced fresh kombucha cheese during 10 days of storage. In all samples, higher ABTS than DPPH radical scavenging activity was determined. Freshly prepared and 10 days stored kombucha cheeses fortified with different types of sage preparations had significantly higher FRAP values than the control sample. All analysed samples had satisfied sensory characteristics and same scores of sensory evaluation after the production. Kombucha fresh cheese with addition of different types of sage preparations can be an innovative and valuable dairy product.

Effects of active batter coatings enriched by quince seed gum and carvacrol microcapsules on oil uptake and quality loss of nugget during frying

ABSTRACT

The effects of active batter coatings containing quince seed gum (QSG) and carvacrol microcapsules (CM) on oil uptake, moisture loss, lipid oxidation, texture, color and organoleptic properties of chicken nuggets during the frying process were investigated. Active coatings on the surface of nuggets reduced oil uptake and moisture loss of fried samples decreased by 33.21% and 29.64%, respectively. Antioxidant activity tests showed that oxygen radical absorbance capacity (ORAC) and DPPH radicals scavenging activity of carvacrol microcapsules were 152.23 ± 4.11 μmol TE/g, and 51.09 ± 3.32%, respectively. Investigation of primary and secondary oxidation products in the fried nugget samples showed that the peroxide value and thiobarbituric acid levels in control samples were 7.43 meq peroxide/kg and 1.35 mg MDA/kg, respectively. The results of this study showed that the highest reduction in PV and TBA were 41.85 and 37.04% for the QSG-coated samples containing 1% carvacrol microcapsules. The color of QSG-coated samples did not change significantly compared to control samples, although their hardness was reduced compared to the control samples (p < 0.05). The results showed that the use of active edible coatings made from quince seed gum and containing carvacrol microcapsules did not show any negative effects on the sensory properties of nuggets.

GRAPHIC ABSTRACT

Effects of polysaccharide-based coatings on postharvest storage life of grape: measuring the changes in nutritional, antioxidant and phenolic compounds

In this study, the effect of postharvest coating of chitosan (CH) 1.0%, gum ghatti (GG) 1.0% and combine of each other, on nutritional properties, phenolic compounds and antioxidant capacity of ‘Rishbaba’ grape (Vitis vinifera L.) was evaluated during 60 days of cold storage. Coating with 1.0% CH solely or in combined with 1.0% GG caused a considerable retain in grape berries phenolic acids compared to uncounted samples after the 60th day. Moreover, flavanols and flavan-3-ols content were found to be highest in fruits treated with CH and GG complex. At the end of storage, the highest concentrations of delphinidin, cyanidin, pelargonidin and malvidin were found in grapes coated with CH in combined with GG. The highest antioxidant capacity and the lowest polyphenol oxidase activity were related to samples treated with CH and GG complex. Also, the combination effects of CH and GG at 1.0% were the most efficient for soluble sugars and polyamines accumulation. The CH + GG complex had the best result on prohibiting grape fungal decay. The results showed a research increase of this complex that these are a strong potential strategy to produce coatings for improving the postharvest quality of fruits and could be considered as a good solution to preserve many components of them.

Characterization of functional sweetened condensed milk formulated with flavoring and sugar substitute

In the present study, the effect of sugar replacement and enrichment with cinnamon extract (CE) on the physicochemical, functional, and organoleptic properties of sweetened condensed milk (SCM) and the production of flavored functional dairy dessert was investigated. The results demonstrated that by adding CE (0.5 and 1%) and fructose sugar (50 and 100% replacement) in the formulation containing maltodextrin, the physicochemical, functional, and organoleptic properties of SCM samples were improved. However, adding fructose and CE at the maximum concentration increased the acidity, particle size, redness (a), yellowness (b) and decreased the lightness (L), viscosity, and sensory scores of the SCM samples (p < .05). Scanning electron microscopy images demonstrated that as the fructose level increased, the number of cavities increased, while the size of the cavities decreased (p < .05). Microstructure analysis also showed that the application of CE increased the density of the structure in the SCM samples. However, the SCM samples formulated with maltodextrin, 0.5% CE, and 50% fructose substitution were identified as optimal samples. Evaluation of the functional properties of SCM formulated with 0.5% CE revealed that the total phenolic content (TPC) and DPPH radical scavenging activity were in the range of 139.21-143.24 mg GAE / g and 50.12%-52.01%, respectively.

Evaluation of the chemical qualities and microstructural changes of Lentinula edodes caused by airborne ultrasonic treatment combined with microwave vacuum drying

This study analyzed a new drying method using airborne ultrasound combined with microwave vacuum to study its effect on the quality characteristics and microstructure of dehydrated L. edodes. Ultrasonic treatment resulted in many micropores in the product, forming the sponge effect caused by ultrasonic waves, which can promote the rapid evaporation of water in the product. Samples of Lentinula edodes individuals were dried using four methods: hot air drying (HAD), microwave vacuum drying (MVD), microwave vacuum drying after ultrasonic pretreatment (US+MVD) and airborne ultrasonic treatment combined with microwave vacuum drying (USMVD). The results showed that USMVD can reduced the loss of total sugar, total phenol, and total antioxidants in L. edodes, and increased the relative content of ergosterol, sulfur compounds, and free amino acids (p < 0.05). Scanning electron microscope observation revealed that USMVD resulted in a uniform reticular porous structure, which could better maintain desirable levels of nutrients. Therefore, USMVD can produce high quality products. PRACTICAL APPLICATION: Airborne ultrasonic waves combined with MVD provides an innovative drying method for mushrooms, which has not been studied at present. The mixed drying method has great potential in maintaining product quality. It provides a theoretical basis for studying drying technology in the future.