Modeling quality changes in tomato paste containing microencapsulated olive leaf extract by accelerated shelf life testing

Effects of free and encapsulated Siah-e-Samarghandi grape seed extract on the physicochemical, textural, microbial, and sensorial properties of UF-Feta cheese

The current study was conducted to elucidate the impact of grape seed extract (SE) and microencapsulated seed extract (MSE) addition to UF-Feta cheese. The SE was encapsulated in maize starch, alginate, and canola oil using the emulsion technique. The SE and MSE characteristics were evaluated. The products were subjected to physicochemical (pH, titrable acidity, color, texture, and sensory properties), microbiological analysis (starter count), and lipid oxidation test (proxide, acid degree, and ansidine value) during 60 days of storage. The main phenol component in the SE was catechin (419.04 mg/L), gallic acid (319.63 mg/L), and chlorogenic acid (4.19 ± 0.002 mg/L). The antioxidant value was 157.80 mg/L. The MSE was elliptical in shape with a 24.29 μm diameter. The efficiency of microencapsulation was 53.86%. The addition of SE and MSE had no significant effect on pH and acidity, but lipolysis decreased based on acid degree value (0.7%; p > .05). The increasing trend of peroxide values was 172.54%, 145.68%, and 118.75% for C, SE, and MSE samples, respectively, and 35.68%, 32.28%, and 17.24% for the P-anisidine values during the storage time. Therefore, fat oxidation was reduced in the supplemented cheese. Nevertheless, the supplemented cheese had limited color alterations. The MSE and SE did not affect the survival rates of the starter count. The SE and MSE had a less rigid structure. The hardness (2748.0 g) and chewiness (57.45 mJ) values in SE cheese had the greatest value among the samples. All sensory parameters were lowest in MSE cheese. In short, encapsulation showed suitable properties for SE to apply in UF-Feta cheese.

Preservation of active components in olive leaf extract by spray drying method in biodegradable polymers: Optimization, in vitro gastrointestinal digestion and application

INTRODUCTION

Encapsulation of the bioactive ingredients in biodegradable and edible polymers is an alternative novel application method to keep these kind of natural products stable.

OBJECTIVE

The purpose is to optimize the encapsulation system of olive leaf extract by spray drying method, and to apply the products into a model food.

METHODS

Olive leaf extract was encapsulated in arabic gum/maltodextrin blend by spray drying method. Combined design approach under I-optimal design type was used to optimize the system. Characterisation studies under moisture content, water activity, solubility, bulk density, tapped density, Carr index, particle size distribution, powder morphology and glass transition temperature were applied to the microparticles obtained under optimum conditions. The bioavailability of the encapsulated active material was tested by in vitro gastrointestinal digestion. Furthermore, microparticles produced under optimum conditions were also evaluated for a potential functional food application.

RESULTS

The optimum conditions were achieved by arabic gum/maltodextrin (3.7:6.3) with 10% (w/v) in the mixture of wall material and active material under 165.5°C to achieve maximum encapsulation efficiency (86.92%), encapsulation yield (71.32%) and antioxidant activity (5.74 mg Trolox equivalent antioxidant capacity/g dry microparticle).

CONCLUSIONS

Olive leaf extract encapsulated in arabic gum/maltodextrin may be a good alternative additive to prevent the lipid oxidation in fat-containing food products as well as improvement of the product quality by functional properties.

Valorizing the usage of olive leaves, bioactive compounds, biological activities, and food applications: A comprehensive review

Olive oil production is a significant source of economic profit for Mediterranean nations, accounting for around 98 percent of global output. Olive oil usage has increased dramatically in recent years, owing to its organoleptic characteristics and rising knowledge of its health advantages. The culture of olive trees and the manufacture of industrial and table olive oil produces enormous volumes of solid waste and dark liquid effluents, involving olive leaves, pomace, and olive oil mill wastewaters. These by-products cause an economic issue for manufacturers and pose major environmental concerns. As a result, partial reuse, like other agronomical production wastes, is a goal to be achieved. Because these by-products are high in bioactive chemicals, which, if isolated, might denote components with significant added value for the food, cosmetic, and nutraceutical sectors, indeed, they include significant amounts of beneficial organic acids, carbohydrates, proteins, fibers, and phenolic materials, which are distributed differently between the various wastes depending on the olive oil production method and table olive agronomical techniques. However, the extraction and recovery of bioactive materials from chosen by-products is a significant problem of their reasonable value, and rigorous detection and quantification are required. The primary aims of this review in this context are to outline the vital bioactive chemicals in olive by-products, evaluate the main developments in extraction, purification, and identification, and study their uses in food packaging systems and safety problems.

Kinetic Modeling of Quality Changes and Shelf Life Prediction of Dried Coconut Chips

The color, texture and rancidity of dried fruit are critical parameters to control for consumer acceptance. The goal of this research was to investigate the kinetics of color parameter changes and texture in terms of the crispness and peroxide value (PV) of dried coconut chips by using zero-, first- and second-order kinetic reactions during storage at different temperatures, as well as shelf life prediction using the accelerated method. The outcomes demonstrated that the zero-order kinetic reaction was appropriate to describe the change in color, crispness and PV of dried coconut chips during storage (R2 = 0.9690–0.9899). The rancidity had a higher correlation than the texture and color changes used to assign the quality essence. The activation energy (Ea) for the PV change was 11.83 kJ/mol. Therefore, the shelf life expectancy of the dried coconut chips was estimated to be 144, 128 and 115 days at 35, 45 and 55 °C, respectively. Meanwhile, the shelf life of products stored at ambient temperature was 159 days, and those products were stored in the refrigerator for 194 days. The findings provide retailers and consumers the ability to choose the ideal temperature and storage time for dried coconut chips in order to ensure the product’s quality.

Alginate-based microparticles structured with different biopolymers and enriched with a phenolic-rich olive leaves extract: A physico-chemical characterization

Encapsulation of olive leaves extracts (OLE), rich of healthy components like Oleuropein, Hydroxytyrosol and Verbascoside, represents a new challenge to improve stability and nutritional value of food as well as a way to recover value added compounds from by-products, contributing to a more sustainable food system. In this context, OLE-loaded microbeads of Na alginate alone or in combination with Pectin, Na Caseinate or Whey protein isolates, were produced by emulsification internal ionotropic gelation. Encapsulation efficiency of the main phenolic compounds (Oleuropein, Hydroxytyrosol, Verbascoside) was carried out along with microparticles morphological characterization by scanning electron microscopy (SEM), thermal properties by differential scanning calorimetry (DSC) and color. Encapsulation efficiency resulted higher for Alginate/Pectin, whilst Alginate/Caseinate was the less performing system, probably due to the lower interaction with polyphenols. SEM revealed collapsed structures and continuous smooth surfaces for Alginate and Alginate/Pectin microbeads while more regular structures and porous surfaces were observed for Alginate/Caseinate and Alginate/Whey proteins. Higher hue angle and lower chroma values were observed for all the beads with respect to the pure extract, indicating a reduction of the yellow/brown color. DSC highlighted higher thermal stability for the microbeads in comparison to the original ingredients, showing also new thermal transitions related to bonds formation between polymers and OLE.

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Verbascoside showed higher encapsulation efficiency compared to Oleuropein.

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Alginate/Pectin was the most efficient system for encapsulation purposes.

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Microstructural traits were linked to the encapsulation efficiency.

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Thermal analysis revealed increased thermal stability of encapsulated polyphenols.

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Encapsulation allowed a mitigation of the color properties of the olive leaf extract.

The challenge of exploiting polyphenols from olive leaves: addition to foods to improve their shelf-life and nutritional value

Olive leaves represent a waste from the olive oil industry which can be reused as source of polyphenols. The most representative phenolic compound of olive leaves is the secoiridoid oleuropein, followed by verbascoside, apigenin-7-O-glucoside, luteolin-7-O-glucoside, and simple phenols. The attention towards these compounds derives above all from the large number of studies demonstrating their beneficial effect on health, in fact olive leaves have been widely used in folk medicine in the Mediterranean regions. Moreover, the growing demand from consumers to replace the synthetic antioxidants, led researchers to conduct studies on the addition of plant bioactives in foods to improve their shelf-life and/or to obtain functional products. The current study overviews the findings on the addition of polyphenol-rich olive leaf extract (OLE) to foods. In particular, the effect of OLE addition on the antioxidant, microbiological and nutritional properties of different foods is examined. Most studies have highlighted the antioxidant effect of OLE in different food matrices, such as oils, meat, baked goods, vegetables, and dairy products. Furthermore, the antimicrobial activity of OLE has been observed in meat and vegetable foods, highlighting the potential of OLE as a replacer of synthetic preservatives. Finally, several authors studied the effect of OLE addition with the aim of improving the nutritional properties of vegetable products, tea, milk, meat and biscuits. Advantages and drawbacks of the different use of OLE were reported and discussed. © 2020 Society of Chemical Industry.

Improving the storage stability of tomato paste by the addition of encapsulated olive leaf phenolics and experimental growth modeling of A. flavus

It is necessary to apply some preservatives for tomato paste since in the harvest season, a high load of tomatoes need to be processed as they are among highly perishable products. Application of antimicrobial extracts or essential oils, as natural preservatives, in their raw forms might reduce their efficiency when they are exposed to environmental conditions. However, microencapsulation is a well-known method to solve this problem. Our main goal was to restrict fungal growth rate in stored tomato paste and increase its storage stability by incorporating encapsulated olive leaf phenolic-rich extract. Total Soluble Solids (TSS), consistency, pH, color indices and diametrical growth rate of Aspergillus flavus were measured for different samples. The treatments designed in terms of considering two levels of non-encapsulated olive phenolics extract with 500 and 1000 ppm (NE₅₀₀ and NE₁₀₀₀), the same levels with encapsulated extract; i.e., 500 and 1000 ppm (ME₅₀₀ and ME₁₀₀₀), and similar levels of the common preservative of sodium benzoate with 500 and 1000 ppm (B₅₀₀ and B₁₀₀₀). Antifungal properties of NE samples were higher than ME ones during storage although ME samples could maintain diametrical growth rate of the fungus more stable than NE ones. NE samples justified lower maximum growth rate than ME samples while ME samples could extend lag phase of microbial growth compared with NE one and delay their internal deteriorative reactions. Among Baranyi, modified Baranyi, Modified Gompertz, and Logistic models, Modified Gompertz model represented the best model and could fit the growth factors of A. flavus on tomato paste with higher R² index as well as lower RMSE and SSE indices. Based on the results obtained, it could be concluded that usage of encapsulated olive leaf extract in tomato paste is an effective, natural and sustainable approach to improve the shelf life of tomato paste since this natural compound could perform as favourable as preservatives; also it could maintain physicochemical as well as microbial properties of tomato paste for a long term. Thus, it is strongly recommended that application of encapsulated olive leaf extract to be considered seriously by the tomato paste industry as it can effectively reduce the mold and fungal contaminations which are very common and prevalent in the plants. The future work in this regard should focus on sensory evaluations when incorporating encapsulated olive leaf extract into tomato paste.

Physical and Sensory Properties of Mayonnaise Enriched with Encapsulated Olive Leaf Phenolic Extracts

This work aimed to study the physical, structural, and sensory properties of a traditional full-fat mayonnaise (≈ 80% oil) enriched with an olive leaf phenolic extract, added as either free extract or encapsulated in alginate/pectin microparticles. Physical characterization of the mayonnaise samples was investigated by particle size, viscosity, lubricant properties, and color; a sensory profile was also developed by a quantitative descriptive analysis. The addition of the extract improved the dispersion degree of samples, especially when the olive leaf extract-loaded alginate/pectin microparticles were used. The encapsulated extract affected, in turn, the viscosity and lubricant properties. In particular, both of the enriched samples showed a lower spreadability and a higher salty and bitter perception, leading to a reduced overall acceptability. The results of this study could contribute to understanding the effects of the enrichment of emulsified food systems with olive by-product phenolic extracts, both as free and encapsulated forms, in order to enhance real applications of research outcomes for the design and development of healthy and functional formulated foods.

Application of gum Arabic and maltodextrin for encapsulation of eggplant peel extract as a natural antioxidant and color source

Our aim was to produce an encapsulated powder loaded with eggplant peel extract as a natural source of color and antioxidants through gum Arabic and maltodextrin. The effect of spray drying inlet temperature (140-170°C) and various carriers (maltodextrin, gum Arabic, and their combination) on powder production yield, physical properties, flowability, color, total phenolic content (TPC), antioxidant activity, infrared spectroscopy (FTIR), microstructure and particle size were investigated. Our results revealed that physicochemical properties of powders were influenced by the carrier type and inlet temperature. Obtained powders by maltodextrin at 170°C showed the highest TPC (5.2mg/g), DPPH (73.4%), ABTS (90.5%), TEAC (2. 5mM), hydroxyl radicals scavenging activity (79.1%) and reducing power (1.2 Abs₇₀₀) among all samples. FTIR spectroscopy indicated that the extract was encapsulated by the carriers. Microstructure evaluation of powders showed some hollow particles with matrix-type structures. Sensory evaluation indicated that addition of encapsulated eggplant extract into the formulation of gummy candy improved its color and overall acceptability.

Double emulsions with olive leaves extract as fat replacers in meat systems with high oxidative stability

Double emulsions (DE) with a healthy oil blend as lipid phase and an olive leave extract (OLE) encapsulated in the internal aqueous phase (DE/OLE) were incorporated as fat replacers in meat systems, in order to improve both the lipid profile and the oxidative stability. After 14 days of storage at 4 °C, DE/OLE showed good physical stability (90% of globule population was still below 10 μm diameter), and high antioxidant capacity (over 80%), longer than time required for this type of food ingredients. A high correlation was found between the remaining oleuropein content and the antioxidant capacity in both meat systems with DE/OLE (MS-DE/OLE) and meat systems with the oil blend as liquid oil and non-encapsulated OLE (MS-L/OLE). MS-DE/OLE were technologically feasible and showed higher retention of oleuropein (69%), oxidative stability and antioxidant capacity at 60 °C for 7 days than MS-L/OLE, where oleuropein was almost depleted. The encapsulation of OLE in DE could be a suitable strategy to avoid lipid oxidation in meat systems with healthier lipid profile.

Prediction of shelf-life and changes in the quality characteristics of semidried persimmons stored at different temperatures

This study was performed to investigate changes in the quality characteristics and shelf-life of semidried persimmons stored at different temperatures using acceleration experiments. In order to estimate quality changes in the samples, we evaluated the physicochemical properties, microbiological changes, and sensory features of the samples periodically after storage at -20, -10, 0, and 10 °C. At all storage temperatures, CIE L ^* a ^* b ^* values decreased significantly. Based on the results of this study, regression equations are set up. L ^* had the highest correlation and were therefore used to determine quality factor. The activation energy, which was calculated using the Arrhenius equation, was found to be 12.98 kcal/mol, and the Q10-values were 3.81, 2.07, and 2.06 at -20 to -10 °C, -10 to 0 °C, and 0 to 10 °C, respectively. Therefore, the expected expiration dates of the semidried persimmons were estimated to be 203.83, 53.46, 22.00, and 8.71 days at -20, -10, 0, and 10 °C.

Shelf Life Extension of Tomato Paste Through Organoleptically Acceptable Concentration of Betel Leaf Essential Oil Under Accelerated Storage Environment

This study was attempted with two objectives: (1) to find an acceptable concentration of betel leaf essential oil (BLEO) based on sensory evaluation that can be employed in tomato paste; (2) to evaluate the effect of the acceptable concentration of BLEO in the paste during accelerated storage under 89 ± 1.2% RH at 39 ± 1 °C. Linguistic data obtained from sensory evaluation of tomato paste treated with 4 different concentrations of BLEO were analyzed using fuzzy logic approach. The organoleptically acceptable concentration was determined to be 0.25 mg/g of BLEO in tomato paste. The effect of the selected concentration of BLEO on different physicochemical and microbial attributes of tomato paste during accelerated storage was studied. Untreated tomato paste was found to have 12% less total antioxidant capacity than treated paste at the end of storage. Based on a^* /b^* value in CIELAB color space, the BLEO treated paste efficiently extended the shelf life by 14 days with respect to untreated paste samples under accelerated storage conditions. BLEO comes with a tag contributing to green consumerism, and its application as food preservative is no less than a value addition to the product.

PRACTICAL APPLICATIONS

Essential oil is considered to have promising potential as an alternative food preservative, and its use is practically possible if they could overcome the sensory barrier, while retaining the preservative potency. The importance of identifying the sensory attributes for commercial success of essential oil treated food product was considered in this study. It contributes to the potency of organoleptically acceptable concentration of BLEO in shelf life extension of tomato paste under accelerated storage conditions. At industrial level, the estimated shelf life of treated tomato paste can be increased by incorporating more hurdles alongside BLEO.

The Effects of Storage Conditions on Lycopene Content and Color of Tomato Hot Pot Sauce

Tomato hot pot sauce (THPS) at different storage temperatures (0, 25, and 37°C) and with two kinds of packaging for 120 days was investigated in this study. High performance liquid chromatography was employed for detecting lycopene and 5-hydroxymethylfurfural (HMF). The changes of lycopene and HMF during storage were regressed with kinetic equation of both zero-order and first-order models, and the latter fitted better. The kinetic equation constant (k value) of lycopene or HMF at 37°C was higher than that at 25°C. The k value of lycopene of PET/PE (P1) packaged THPS was 1.60 times of that of PET/Al/EAA/PE (P2) packaged at 37°C, while it was 2.12 times at 25°C. The k value of HMF of P1 packaged THPS was 1.69 times of that of P2 packaged at 37°C, while it was 1.01 times at 25°C. Significant correlations between color index of L⁎, a⁎, and a⁎/b⁎ and lycopene or HMF were found at storage temperature. Browning color was attributed to both Maillard reaction and degradation of lycopene. In conclusion, lower storage temperature and stronger oxygen barrier property of package could maintain color stability and extend shelf life.

Arrhenius equation modeling for the shelf life prediction of tomato paste containing a natural preservative

BACKGROUND

The shelf life of tomato paste with microencapsulated olive leaf extract was compared with that of samples containing a commercial preservative by accelerated shelf life testing. Based on previous studies showing that olive leaf extract as a rich source of phenolic compounds can have antimicrobial properties, application of its encapsulated form to improve the storage stability of tomato paste is proposed here.

RESULTS

Regarding total soluble solids, the control and the sample containing 1000 µg g^-1 sodium benzoate had the lowest (Q₁₀  = 1.63) and highest (Q₁₀  = 1.88) sensitivity to temperature changes respectively; also, the microencapsulated sample containing 1000 µg g^-1 encapsulated olive leaf extract (Q₁₀  = 1.83) followed the sample containing 1000 µg g^-1 sodium benzoate in terms of the highest kinetic rates. In the case of consistency, the lowest and highest activation energies (E_a ) corresponded to samples containing 1000 µg g^-1 non-encapsulated olive leaf extract and 1000 µg g^-1 microencapsulated olive leaf extract respectively.

CONCLUSION

Interestingly, samples containing microencapsulated olive leaf extract could maintain the original quality of the tomato paste very well, while those with non-encapsulated olive leaf extract rated the worst performance (among all specimens) in terms of maintaining their quality indices for a long time period. Overall, the shelf life equation was able to predict the consistency index of all tomato paste samples during long-time storage with high precision. © 2017 Society of Chemical Industry.

Effect of ultraviolet irradiation on postharvest quality and composition of tomatoes: a review

Ultraviolet (UV) irradiation has recently emerged as a possible alternative to currently used postharvest phytosanitary treatments. Research has also highlighted other benefits associated with UV irradiation in postharvest technology. This review presents the effects of UV irradiation on postharvest and nutritional quality of tomatoes. The application of UV irradiation on tomatoes is discussed including its effect on biological (respiration rate, ethylene production and microbial growth), physico-chemical (firmness, colour, total soluble solids and titratable acidity) and nutritional (vitamins, carotenoids, phenolic and antioxidants) quality. UV-treated tomatoes have shown resistance to microbial growth and decay. Although UV irradiation reduces the loss of vitamin C during storage, the loss of vitamin E remains a concern. UV treatments lead to higher antioxidant capacity, flavonoids and phenolic content. UV irradiation significantly reduced carotenoids in certain cultivars. Based on the literature reviewed, the success of UV irradiation treatments is cultivar-dependent. While improved retention of phytochemicals has been reported in UV-C treated fruit, increased losses have been reported in certain cultivars. Research efforts on the development of cultivar-specific UV irradiation protocols are warranted. The effect of harvest maturity and seasonal differences in the efficacy of UV treatments is required to be investigated.

Valorization of functional properties of extract and powder of olive leaves in raw and cooked minced beef meat

BACKGROUND

Olive leaves (OL), available in huge amounts from pruning, are known to be a useful source of biologically active compounds. This study investigated the potential application of OL as a supplement to minced beef meat in order to develop a functional product. The effect of OL extract or powder (100 and 150 µg phenols g^-1 meat) on the quality and stability of raw and cooked meat during refrigerated storage was examined.

RESULTS

Microwave drying at 600 W gave OL with the highest antioxidant quality (evaluated by TEAC/[phenols] (mg mg^-1 ) and DPPH/[phenols] (mg mg^-1 )) compared with other methods. OL showed an ability to inhibit (P < 0.05) lipid oxidation (TBARS values (mg MDA kg^-1 ) were reduced by 25-65%) and myoglobin oxidation (metmyoglobin production was 43-65% in control samples and 14-35% in treated samples). OL also improved the technological quality of the meat, decreasing (P < 0.05) storage loss (%) and defrosting loss (%) without affecting cooking loss (%) and Napole yield (%). Sensory properties were not modified by the added ingredient at the tested levels (P < 0.05).

CONCLUSION

OL (extract or powder) may have applications in the development of functional meat products of good technological quality that remain stable during storage. © 2016 Society of Chemical Industry.

The Influence of Refractance Window Drying on Qualitative Properties of Kiwifruit Slices

In this research, effect of Refractance Window (RW) drying on the quality properties of the kiwifruit samples was investigated. Drying temperatures of 80–100 °C, slice thickness of 0.8–2.4 mm and Mylar thickness of 100–300 µm were the independent variables and different qualitative attributes including drying duration, textural hardness, colour, rehydration ratio and organoleptic properties were responses monitored in each situation. Drying temperature was the most important factor contributed to quality features of RW dried kiwifruits with significant effects on all properties. Similarly, slice thickness influenced nearly all quality traits except textural hardness and some colour indices. However, Mylar membrane thickness failed to affect about every qualitative property of kiwifruit samples significantly. The majority of organoleptic properties of RW dried kiwifruits, including flavour, colour, texture, shrinkage and overall acceptance, were judged to be in the range of medium to good quality (scores of 3–4) by panellists.