Antioxidant capacity versus chemical safety of wheat bread enriched with pomegranate peel powder

Comparative study on effect of pomegranate peel powder as natural preservative and chemical preservatives on quality and shelf life of muffins

This research aims to investigate the potential of utilizing pomegranate peel powder (PPP) as a natural preservative in muffin preparation. Pomegranate peel is a rich source of bioactive compounds, including phenolics, flavonoids, and tannins, which possess high antioxidant and antimicrobial properties. The In-Vitro antifungal activity of pomegranate peel powder (8% PPP), potassium sorbate (0.1% PS) and calcium propionate (0.5% CP) was assessed against Penicillium sp. and Aspergillus sp. using poison food technique. The PPP showed the anti-fungal activity by delaying the growth of microorganism on media plate similar to the PS and CP. The effect of utilization of PPP on quality characteristics of muffins were compared with the muffins with chemical preservatives (0.1% PS and 0.5% CP). The viscosity and specific gravity of batter significantly increased from 7.98 to 11.87 Pa s and 1.089-1.398 respectively on addition of 8% PPP. The optical microscopic structure of PPP added batter revealed the decrease in the number of air cells from 24 to 12 with radius range of 6.42-72.72 μm and area range of 511.03-15,383.17 µm2. The functional properties of flour with PPP had higher water absorption capacity, foaming stability, emulsification activity and emulsion stability than others. The addition of PPP significantly increase the weight (32.83 g), and decrease the height (31.3 mm), volume (61.43 cm3), specific volume (1.67 cm3/g) and baking loss (10.19%). The 418.36% increase in fibre content, 14.46% and 18.46% decrease in carbohydrates and energy value was observed in muffin with 8% PPP as compared to control respectively. The total phenols was increased from 0.92 to 12.5 mg GAE/100 g, total tannin from 0.2 to 8.27 mg GAE/100 g, In-vitro antioxidant activity by DPPH from 6.97 to 29.34% and In-vitro antioxidant activity by FRAP from 0.497 to 2.934 mg AAE/100 g in muffins added with 8% PPP. The muffin with PPP was softer than control and muffin with 0.1% PS. The addition of PPP resulted to improve in muffin texture but taste slightly bitter. During the storage of muffins at room temperature (27-30 °C), the moisture content of muffin with PPP was reduced from 17.04 to 13.23% which was higher than the rest of the treatments. Similarly, the hardness of sample with PPP was higher than the sample with 0.5% CP, but lowers than control and sample with 0.1% PS throughout the storage period. The results suggest that pomegranate peel powder can be successfully used as a natural preservative in place of chemical preservatives in muffins, to extend the shelf life. This study provides the opportunity to use PPP as functional ingredient and natural preservative in different bakery products.

Development of fiber-enriched muffins using pomegranate peel powder and its effect on physico-chemical properties and shelf life of the muffins

BACKGROUND

Pomegranate peel is a by-product from the pomegranate processing industries and is a rich source of dietary fibers and bioactive compounds. It has good antioxidant and antimicrobial properties. In the present study, the effects of substitution of refined wheat flour with pomegranate peel powder (PPP) at a rate of 2%, 4%, 6%, 8% and 10% on the physico-chemical and sensorial properties as well as on the oxidative and microbial stability of muffins were investigated.

RESULTS

A significant reduction in specific volume (1.99 to 1.57 cm3  g-1 ), weight loss (11.73 to 10.14 g 100 g-1 ) and an increase in crumb hardness (633.06 to 2311.5 g) of muffins were observed on addition of PPP. Moreover, the nutritional value was improved by a significant increase in the fiber content (4.39 to 10.66%), total phenols (0.443 to 48.53 mg GAE 100 g-1 ), antioxidant activity (75.94% to 99.36%), calcium (200.33 to 294.33 mg 100 g-1 ), potassium (227.33 to 425.33 mg 100 g-1 ) and magnesium (96.33 to 288.33 mg 100 g-1 ). The pasting and rheological properties of muffin batter showed a significant decrease in the final and peak viscosity, as well as increase in storage, loss and complex modulus. The muffin samples were organoleptically acceptable up to a level of 8% PPP. Free fatty acid content, peroxide value and microbial count of the muffin with 8% PPP were significantly lower compared to the control sample and more oxidatively and microbially stable for a storage period of 21 and 28 days at ambient and refrigerated temperatures, respectively.

CONCLUSION

The present study provides the opportunity to use PPP as functional ingredients and natural preservative in the preparation of muffins. © 2023 Society of Chemical Industry.

Pulp from Colored Potatoes (Solanum tuberosum L.) as an Ingredient Enriching Dessert Cookies

Freeze-dried pulp from colored potatoes, obtained after starch isolation, is a rich source of polyphenols. Therefore, it can be used to fortify cookies, contributing to a reduction in industrial waste, aligning with the zero-waste technology. The purpose of this study was to analyze the effects of adding 5% and 10% pulp from two varieties of colored potatoes on the content of polyphenols, antioxidant activity, physical characteristics, nutritional composition, and the levels of hydroxymethylfurfural and acrylamide of the fortified cookies. The findings revealed that colored potato pulp is an outstanding additive for fortifying cookies with polyphenols, flavonoids, anthocyanins, and flavonols (even two to four times in comparison to control). Cookies containing pulp exhibited even two times higher fiber and protein content (up to 17% more), while the fat and ash content remained unchanged compared to control cookies. Furthermore, they contained 30% less HMF and 40% more acrylamide. These cookies also exhibited good physical properties in the final products. The study demonstrated that pulp from the "Magenta Love" potato variety was significantly more effective in enriching cookies with health-promoting compounds and nutrition value compared to pulp from Marleta Blue.

The effects of pomegranate peel added bread on anthropometric measurements, metabolic and oxidative parameters in individuals with type 2 diabetes: a double-blind, randomized, placebo-controlled study

BACKGROUND/OBJECTIVES

The aim of this study was to evaluate the sensory properties of antioxidant-rich bread made by adding pomegranate peels and their effects on anthropometric measurements and metabolic and oxidative parameters of individuals with type 2 diabetes after consumption.

SUBJECTS/METHODS

This randomized, double-blind, placebo-controlled study was conducted with 22 individuals aged between 19 and 64 years who had been diagnosed with type 2 diabetes for at least 5 years, used only metformin, did not lose more than 10% of their body weight in the last 6 months, and had a body mass index of ≥ 25.0 kg/m². While the study group (n = 11) consumed bread containing 500 mg pomegranate peel daily for 8 wk, the control group (n = 11) consumed standard bread. Anthropometric measurements and metabolic and oxidative parameters of individuals were evaluated at the beginning and end of the study.

RESULTS

Decreases were detected in the waist circumference, waist/hip and waist/height ratios, body fat percentages, blood pressure, and serum insulin, triglyceride, and total cholesterol levels in the individuals in the treatment group, compared with those in the control group (P < 0.05).

CONCLUSIONS

Pomegranate peel consumption by individuals with type 2 diabetes may have positive effects on anthropometric measurements and glycemic and lipid parameters.

A Feasible Approach to Developing Fiber-Enriched Bread Using Pomegranate Peel Powder: Assessing Its Nutritional Composition and Glycemic Index

The consumption of dietary fiber (DF) has been associated with a reduced incidence of non-communicable diseases. Despite various strategies implemented worldwide to increase DF intake, it remains low. Therefore, the development of new fiber-rich food products that are widely consumed could be a strategy to improve DF intake. In this study, an agro-industrial by-product, pomegranate peel powder (PPP), was used as an innovative source of DF and antioxidant. The objective was to develop a bread enriched with DF, antioxidants, and sensory characteristics by partially replacing wheat flour (WF) with PPP at levels of 0%, 2.5%, 5%, 7.5%, and 10%. Bread with 2.5% and 5% PPP was chosen for a clinical trial to evaluate glycemic response (GR) in healthy subjects and determine the bread's glycemic index (GI). As the percentage of PPP increased, both the DF and total polyphenol content increased significantly. The highest overall acceptability was achieved with bread containing up to 5% PPP. Consumption of bread with 2.5% and 5.0% PPP significantly reduced the GI compared to the control bread, while the decrease in GR was not significant. PPP could be a potential food and low-cost ingredient to improve the bread's nutritional quality through its contribution to DF and antioxidants.

Exploring the Potential of Pomegranate Peel Extract as a Natural Food Additive: A Review

PURPOSE OF THE REVIEW

Pomegranate is one of the super fruit and a storehouse of several antioxidants and health-promoting compounds which can act as a natural food additive. The pomegranate processing industry generates huge quantities of by-products, particularly peels (50% of fresh fruit weight), that cause environmental pollution due to improper disposal. In this perspective, the present review article focuses on the chemical composition of pomegranate peel and its application as a natural food additive in different food products such as bakery, dairy, meat/meat products, fish/fish products, edible oils, and packaging materials.

RECENT FINDINGS

There is a continuous demand for processed foods exhibiting natural food additives over foods containing synthetic additives/colorants, which can cause serious health implications such as cancer with regular consumption. The food industry is looking for an alternative to synthetic/artificial food additives. To overcome these problems, pomegranate peel or its extract can be used as a natural biopreservative in food products that are prone to fat oxidation and microbial growth. Pomegranate peel contains bioactive compounds, especially tannins, phenolic acids, and flavonoids, which have nutraceutical value and possess higher antioxidant activity and antimicrobial properties. Due to these properties, pomegranate peel prevents lipid oxidation in fatty foods and can also retard the microbial growth.

Punica Granatum Peel Waste- An Underutilized Substrate of Therapeutic Potential: An Overview

India is the second largest consumer and producer of fruits globally. It leads to ample solid waste per year from fruit processing industries that have been proven hazardous to the surroundings. Punica granatum (Pomegranate) belongs to the Lythraceae subfamily Punicoideae, which exhibits immense nutritional properties and delicious flavoring components. The weight of this fruit mainly consists of peel, i.e., 50%, followed by 40% of arils and 10% of seeds. Thus, the major byproduct is a peel that holds many valuable bioactive compounds in higher concentrations viz saponins, carotenoids, steroids, polyphenols, quercetin derivatives, caffeic acid, phenolic acids, flavonoids, ellagitannins, p-coumaric acid, chlorogenic acid, quinic acid, anthocyanidins, triterpenoids, glycosides, tannins, and many more. Consequently, it results in wide-ranging therapeutic applications, including antioxidative, anti-microbial, antihypertensive, anti-carcinogenic, anti-genotoxic, anti-inflammatory, glucoregulation, cardio-protective, hepato-protective and nephroprotective effects along with prebiotic potential. Considering their nutritional and therapeutic aspects, these peels can be used for many purposes rather than being disposed of. With a value-added approach, it is utilized in many food and non-food sectors. So, this review aims to explore the therapeutic potential of P. granatum peel and enlighten its diverse applications in the food industry.

Optimization of reaction conditions for the design of cereal-based dietary fibers with high antioxidant capacity

BACKGROUND

Bound antioxidants are distinguished by their strong potential to defend the body against oxidative stress. Cereal bran fractions contain antioxidant compounds bound to dietary fiber, but this only occurs to a limited extent. Increasing the quantity of bound antioxidant compounds using soluble phenolic compounds is thought to be a possible method for designing cereal-based dietary fibers with high antioxidant potential. Certain cereal bran samples (wheat, oat, rye, and rice) were reacted with different concentrations of beverages (green tea infusion, black tea infusion, espresso, and red wine), rich in various soluble phenolic compounds. The interactive effects of parameters (time, temperature, and pH) and the optimum conditions for the reaction were determined using response surface methodology.

RESULTS

Green tea infusion (30 g·L^-1 ) was found to be the most effective beverage. The pH rather than the time and temperature had significant (O p < 0.0001) effects on the reaction. Neutral or slightly alkaline conditions (pH 7.0-7.9) and mild temperatures (at about 50 °C) were found to be optimum to increase the antioxidant capacity of cereal bran samples. The total antioxidant capacity of oat bran treated with green tea infusion under optimum conditions (53.3 °C, pH 7.4, 60.0 min) reached 226.42 ± 0.88 mmol Trolox equivalent·kg^-1 . The free amino groups in cereal bran were also found to decrease (32-95%) after treatment.

CONCLUSION

It is possible to design functional cereal-based dietary fibers, rich in bound antioxidant compounds through treatment with green tea infusion under optimum conditions. © 2022 Society of Chemical Industry.

Development of High Dietary Fibre-Enriched Cupcake Using Pomegranate Peel Powder

The effect of substituted wheat flour with pomegranate peel powder (PPP) at different ratios 5, 10, 15, and 20% on chemical composition, physical properties, color appearance, staling, and the sensory evaluation of the high-fibre cupcake was evaluated. The obtained results revealed that a slight increase in ash of cake samples with all levels of PPP was found. The highest value of ash was 1.92% given by cupcakes with 20% PPP. It was observed that a gradual significant ( $p\le 0.05$ ) increase in dietary fibre of prepared cupcakes with PPP compared to control cake. The dietary fibre values ranged from 2.73% for the control cake to 17.00% with 20% of PPP; it may be due to the high content of ash and dietary fibre in PPP. Also, using PPP in cupcake manufacturing had a lowered effect on their volume and specific volume, where control cupcake recorded 48.00 cm3 and 1.40 cm3/g for volume and specific volume, respectively. In addition, a gradual significant ( $p\le 0.05$ ) decrease in $L$ value (lightness) with incorporated different levels of PPP was found. The control cupcake had the highest lightness value (65.97) with a significant ( $p\le 0.05$ ) increase compared to all other cupcake samples that ranged between 37.67 and 30.18 by 5% and 20% of PPP, respectively. The results indicated that the highest value of taste was 18.75, which was given by cupcake with 5% PPP. While increasing the percentage of PPP in cupcake, the taste is less acceptable by panelists, and perhaps, this decreases in taste due to the high ratio of fibre in PPP. The highest staling was given by cupcake replaced with PPP at 20% after the ninth day of storage. Finally, it can be concluded that PPP can be used in cupcake production to raise its dietary fibre and mineral content up to a substitution rate of 10% PPP while retaining acceptable organoleptic properties.

Utilization of Vegetable and Fruit By-products as Functional Ingredient and Food

With the constant growth of the human population, the global demand for food is increasing annually. Food security is an arising issue due to decreased resources and massive waste production from the agricultural sector. For example, not all parts of fruits and vegetables are consumed by consumers, and this phenomenon can lead to huge amounts of food wastes that are produced globally. Moreover, non-utilized agriculture by-products, including seed coat, hull, husk, peels, seeds, and pomace, can cause environmental issues. Hence, efficiently utilizing food wastes, such as vegetable and fruit by-products, could be a way to increase food sustainability, and in line with the United Nations Sustainable Development Goal (SDG) to ensure sustainable consumption and production patterns. Moreover, certain agriculture by-products are reported to have a high nutritional value and could be potentially used as functional ingredient and food in the food industry. This review article summarizes findings on the development of new functional foods by utilizing different types of agriculture by-products, that is, vegetable and fruit by-products as ingredients. Furthermore, the nutritional values, processing methods, product acceptability, and potential uses of these vegetable and fruit by-products are also discussed. These by-products can be an alternative source of nutrients to support the global demand for functional foods and as one of the strategies to cope with food insecurity. Studies have shown that different types of fruit and vegetable by-products were well-incorporated in the development of functional foods, such as bakery products and dairy products. Of great importance, this review article provides an insight of the nutritional value, health benefits, and utilization of fruit and vegetable by-products.

Overcoming bread quality decay concerns: main issues for bread shelf life as a function of biological leavening agents and different extra ingredients used in formulation. A review

As is widely accepted, the quality decay of freshly baked bread that affects product shelf life is the result of a complex multifactorial process that involves physical staling, together with microbiological, chemical and sensorial spoilage. In this context, this paper provides a critical review of the recent literature about the main factors affecting shelf life of bread during post-baking. An overview of the recent findings about the mechanism of bread staling is firstly provided. Afterwards, the effect on staling induced by baker's yeasts and sourdough as well as by the extra ingredients commonly utilized for bread fortification is also addressed and discussed. As inclusion/exclusion criteria, only papers dealing with wheat bread and not with long-life bread or gluten-free bakery products are taken into consideration. Despite recent developments in international scientific literature, the whole mechanism that induces bread staling is far from being completely understood and the best analytical methods to be adopted to measure and/or describe in depth this process appear still debated. In this topic, the effects induced on bread shelf life by the use of biological leavening agents (baker's yeasts and sourdough) as well as by some extra ingredients included in the bread recipe have been individuated as two key issues to be addressed and discussed in terms of their influence on the kinetics of bread staling. © 2020 Society of Chemical Industry.

Processing Factors Affecting the Phytochemical and Nutritional Properties of Pomegranate (Punica granatum L.) Peel Waste: A Review

Pomegranate peel has substantial amounts of phenolic compounds, such as hydrolysable tannins (punicalin, punicalagin, ellagic acid, and gallic acid), flavonoids (anthocyanins and catechins), and nutrients, which are responsible for its biological activity. However, during processing, the level of peel compounds can be significantly altered depending on the peel processing technique used, for example, ranging from 38.6 to 50.3 mg/g for punicalagins. This review focuses on the influence of postharvest processing factors on the pharmacological, phytochemical, and nutritional properties of pomegranate (Punica granatum L.) peel. Various peel drying strategies (sun drying, microwave drying, vacuum drying, and oven drying) and different extraction protocols (solvent, super-critical fluid, ultrasound-assisted, microwave-assisted, and pressurized liquid extractions) that are used to recover phytochemical compounds of the pomegranate peel are described. A total phenolic content of 40.8 mg gallic acid equivalent (GAE)/g DM was recorded when sun drying was used, but the recovery of the total phenolic content was higher at 264.3 mg TAE/g when pressurised liquid extraction was performed. However, pressurised liquid extraction is costly due to the high initial investment costs and the limited possibility of carrying out selective extractions of organic compounds from complex peel samples. The effects of these methods on the phytochemical profiles of pomegranate peel extracts are also influenced by the cultivar and conditions used, making it difficult to determine best practice. For example, oven drying at 60 °C resulted in higher levels of punicalin of 888.04 mg CE/kg DM compared to those obtained 40 °C of 768.11 mg CE/kg DM for the Wonderful cultivar. Processes that are easy to set up, cost-effective, and do not compromise the quality and safety aspects of the peel are, thus, more desirable. From the literature survey, we identified a lack of studies testing pretreatment protocols that may result in a lower loss of the valuable biological compounds of pomegranate peels to allow for full exploitation of their health-promoting properties in potentially new value-added products.

Plant-Based Food By-Products: Prospects for Valorisation in Functional Bread Development

The industrial and small-scale processing of plant-based food materials is associated with by-products that may have a negative impact on the environment but could add value to bread-based products. The bioactivity of plant-based food by-products, their impact on the properties of functional bread, and their bioavailability/bioaccessibility leading to potential health effects when consumed was reviewed. Plant-based food by-products which may be added to bread include rice bran, wheat bran, corn bran, grape pomace/seed extract, tomato seed/skin, and artichoke stems/leaves. These by-products contain high concentrations of bioactive compounds, including phenolics, bioactive peptides, and arabinoxylan. Pre-treatment procedures, including fermentation and thermal processing, impact the properties of plant-based by-products. In most cases, bread formulated with flour from plant-based by-products demonstrated increased fibre and bioactive compound contents. In terms of the sensory and nutritional acceptability of bread, formulations with an average of 5% flour from plant-based by-products produced bread with acceptable sensory properties. Bread enriched with plant-based by-products demonstrated enhanced bioavailability and bioaccessibility and favourable bioactive properties in human blood, although long-term studies are warranted. There is a need to investigate the bioactive properties of other underutilised plant-based by-products and their potential application in bread as a sustainable approach towards improving food and nutrition security.

Effect of addition of Opuntia ficus-indica mucilage on the biological leavening, physical, nutritional, antioxidant and sensory aspects of bread

The addition of active compounds to enhance the functional properties of foods is a quite common practice. Recently, bread became one of the target foods to incorporate functional ingredients such as those deriving from Opuntia spp. So far, only Opuntia ficus-indica cladodes in powder has been tested. The addition of fresh O. ficus-indica mucilage (in substitution to water) did not influence the biological leavening of the doughs. The resulting breads showed a biological role of the cactus mucilage, because their antioxidant activity was higher than that of control wheat bread. The sensory analysis indicated a general appreciation of the breads enriched with O. ficus-indica mucilage by the judges. The inclusion of fresh cactus mucilage in bread production might increase the dietary antioxidant intake due to its daily worldwide consumption.

Effect of sea-buckthorn pulp and flaxseed residues on quality and shelf life of bread

Sea-buckthorn and flaxseed residues are high-value materials with potential application in bread-baking.

Polyphenol composition and antioxidant properties of vegetable leaf-fortified bread

The aim of this work was to determine the antioxidant properties of aqueous extracts of vegetable leaf-fortified bread as well as estimate the contents of polyphenolic compounds. Enriched bread was produced from wheat flour fortified at 1, 2, and 3% (w/w) with dried leafy vegetable powders from Amaranthus viridis, Solanum macrocarpon, and Telfairia occidentalis. Gallic acid was the most abundant soluble polyphenol in the control bread and the content in the control bread was significantly higher (p < 0.05) than in all the fortified bread samples. Fortification of bread especially at 3% level resulted in significantly (p < 0.05) higher concentrations of other polyphenols (myricetin, catechin, quercetin, and rutin) compared to the control bread. The fortified bread extracts had significantly (p < 0.05) more effective antioxidants than the control for DPPH radical scavenging activity, ferric iron reducing antioxidant power, metal chelation, and inhibition of linoleic acid peroxidation. PRACTICAL APPLICATIONS: Bread is one of the consumed foods and could be used as a suitable carrier of bioactive compounds. Leafy vegetables contain high levels of polyphenols that could provide beneficial effects by contributing to improved health status of consumers. Therefore, incorporation of leafy vegetables into leavened bread could provide a means of enhancing polyphenol consumption. In this work, we showed that soluble polyphenols were enriched in vegetable-fortified bread. The polyphenol-rich extracts of the fortified bread demonstrated better free radical scavenging and inhibition of unsaturated fatty acid oxidation activities than the regular bread. Therefore, regular consumption of vegetable leaf-fortified bread could lead to reduced oxidative stress and associated chronic diseases in human beings. The vegetable leaf fortification could also serve as a suitable means of enhancing the shelf life of wheat bread.

Fortification of whole wheat flour with different iron compounds: effect on quality parameters and stability

The aim of this study was to evaluate the effects of fortification of whole wheat flour with different iron compounds, such as ferrous sulfate (FS), ferrous fumarate (FF), reduced iron (RI), ferric sodium ethylenediaminetetraacetate (NaFeEDTA), microencapsulated ferrous sulfate (FSm) and microencapsulated ferrous fumarate (FFm), on quality parameters: color, titratable acidity, peroxide value (PV) and hexanal values, during 120 days of storage. An iron content of 1.38 mg/100 g was quantified in non-fortified whole wheat flour and after fortification, the iron levels ranged from 4.80 to 6.29 mg/100 g. The fortification of whole wheat flour with different iron compounds showed changes on the quality parameters evaluated during storage with exception of the color. The whole flour acidity was affected mainly by NaFeEDTA. Compounds FS and FFm presented the highest PV in whole flour after 30 days of storage. Whole flours fortified with FS and FSm presented higher hexanal levels after 30 and 90 days of storage, respectively. Whole flours fortified with RI and NaFeEDTA presented more stability on quality parameters evaluated during storage period. Therefore, the different iron compounds, when used on whole wheat flour fortification, affect differently the quality of the product during storage.

Evaluation of microfiltration and heat treatment on the microbiological characteristics, phenolic composition and volatile compound profile of pomegranate (Punica granatum L.) juice

BACKGROUND

Since processing technology and storage may influence the sensory and nutritional value as well as the shelf life of pomegranate juice (PJ), mild technologies based on microfiltration may be a promising alternative to heat treatments for fruit juice preservation. In this study, physicochemical and microbiological properties of raw (RPJ), microfiltered (MPJ) and cloudy pasteurized (PPJ) PJ were compared over a period of 4 weeks.

RESULTS

Data demonstrated that microfiltration was comparable to pasteurization in guaranteeing microbiological stability of the juice, avoiding spoilage of the final product. After treatment, PPJ showed the highest amounts of gallic acid (GA) and ellagic acid derivatives (EAs). During storage, the amount of ellagitannins, EAs and GA similarly decreased in all types of juice. Trends towards variations of monomeric anthocyanins in MPJ and variations of polymeric and copigmented anthocyanins in both MPJ and PPJ were found over storage.

CONCLUSION

The optimization of pretreatments and filtration parameters can lead to the industrial scale-up of microfiltration technology for the development of high-quality non-heat-treated PJ. © 2017 Society of Chemical Industry.

Nutrient, phytochemical, and antinutrient composition of Citrus maxima fruit juice and peel extract

Nutrient, phytochemical, and antinutrient composition of Citrus maxima fruit juice and peel extract were determined. The fruit was procured from a garden in Trans-Ekulu, Enugu East Local Government Area, Enugu State, Nigeria. Mature undamaged Citrus maxima fruits were thoroughly washed with distilled water to remove contamination, dirt, and air-dried. The peel was separated from the pulp. The pulp (100 g) was blended and filtered through a muslin cloth to obtain a clear juice. The peel (50 g) was macerated with 200 ml of ethanol for 20 min. The peel extract was filtered through filter paper. The supernatant was concentrated by rotary evaporation. The peel extract was weighed and stored in a plastic container until needed. Proximate, mineral, vitamins, antinutrient, and phytochemical composition of the juice and peel extract were determined using standard procedures. Citrus maxima peel extract contains significantly (p < .05) higher crude fiber (2.58%), fat (9.74%), ash (2.49%), and carbohydrate (71.57%) compared with Citrus maxima juice. Alkaloid, phenolics, and flavonoids were also significantly (p < .05) higher in the peel extract. The mineral composition revealed the order Ca > Na > Ph > Fe > Mg > K in the juice and Ca > Ph > Na > Fe > K > Mg in the peel extract. Vitamin C content of the juice and peel extract were 26.36 mg/100 g and 19.34 mg/100 g, respectively. Citrus maxima peel is highly nutritive and rich in phytochemicals, further research is recommended to investigate its therapeutic effect.

A heating method for producing frozen pizza ingredients with increased total polyphenol content and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity

Despite growing demand for more healthful frozen pizza, current technologies for increasing potential healthfulness such as reformulation or enrichment of raw ingredients may lead to undesirable changes in the final product. This study evaluated alternative heat treatments of selected frozen pizza ingredients as methods for increasing the healthfulness of frozen pizza. Four common vegetable toppings (i.e., onion, corn, Japanese green pepper, and red pepper) were heated on a 250°C hot plate, and commercially available par-baked pizza base was reheated at 500°C for 50 s to induce browning. These alternatively heat-treated (AHT) ingredients were compared to their conventional counterparts (e.g., steam-blanched vegetable toppings and commercially available par-baked pizza base, respectively) in terms of total polyphenol content (TPC) and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH RSA). TPC increased and was correlated with internal temperature for onion and peppers during alternative heat treatment, while increases in DPPH RSA of AHT onion and pizza base may be due to the formation of Maillard reaction products. Replacing conventional samples with AHT counterparts increased TPC and DPPH RSA by 1.2-fold to 1.6-fold and 1.3-fold to 2.1-fold, respectively, for vegetable toppings after reheating at 230°C for 12 min. Significant differences in acceptability of sensory attributes (i.e., appearance, taste, aroma, texture, and overall preference) were not observed between AHT and conventional vegetable topping when incorporated into pizza. These results suggest that alternative heat treatment of raw ingredients, particularly vegetable toppings, for the purpose of increasing TPC and DPPH RSA may be a viable method for increasing the potential healthfulness of frozen pizza.

Effect of fiber sources on fatty acids profile, glycemic index, and phenolic compound content of in vitro digested fortified wheat bread

In this study, some dietary fiber (DF) sources were investigated as fortifiers of wheat bread: oat (OB), flax (FB), and apple (AB). Adding oat and flax fibers to bread significantly changed the fatty acid profiles. OB was highest in oleic acid (33.83% of lipids) and linoleic acid (24.31% of lipids). Only in FB, γ-linolenic fatty acid was present in a significant amount-18.32%. The bioaccessibility trails revealed that the DF slow down the intake of saturated fatty acids. PUFA were least bioaccessible from all fatty acids groups in the range of (72% in OB to 87% in FB). The control bread had the greatest value (80.5) and was significantly higher than values for OB, FB, and AB in terms of glycemic index. OB, FB and AB addition led to obtain low glycemic index. AB had a significant highest value of total phenolic (897.2 mg/kg) with the lowest values in FB (541.2 mg/kg). The only significant lowering of caloric values in this study was observed in AB. The study could address the gap in the area of research about taking into consideration glycemic index, fatty acid profile and phenolic content in parallel in terms of DF application in breads.

In vitro bioaccessibility and functional properties of polyphenols from pomegranate peels and pomegranate peels-enriched cookies

Obesity is an urgent social problem and new functional foods providing polyphenols and dietary fibers (DF) may be promising tools to modulate oxidative stress, inflammation and energy homeostasis. Pomegranate peels (PPe) are an agro-industrial by-product containing polyphenols such as ellagitannins (ETs), gallic acid (GA), ellagic acid (EA) and its derivatives (EAs), as well as DF. In this study, PPe enriched cookies (PPeC) were developed, and the bioaccessibility as well as the ability of their polyphenols to exert antioxidant activity along the Gastro-intestinal Tract (GiT) and to modulate digestive enzymes were evaluated in vitro. Data showed that the potential bioaccessibility of ETs was 40% lower from PPeC than PPe whereas EAs' and GA bioaccessibility increased by 93% and 52% for PPeC compared to PPe. The concentration of the polyphenols at each digestion step was associated with the total antioxidant capacity of the potentially bioaccessible material. Moreover the polyphenols released in the simulated duodenal phase upon PPeC digestion exhibited inhibitory activity towards α-glucosidase, α-amylase and lipase, being α-glucosidase > α-amylase > lipase. In conclusion, the data demonstrated that the inclusion of PPe at 7.5% in a bakery product potentially led to a high bioaccessibility of ETs' degradation products (mainly EA and EAs) in the duodenum, with a consequent antioxidant protection along the GiT and modulation of glucose metabolism. Further human studies are warranted to evaluate whether these effects also occur in vivo.

Bread formulated with guava powder was enriched in phenolic and aroma compounds, and was highly acceptable by consumers

Guava powder (GP) was used as source of aroma and phenolic compounds to fortify wheat bread 10% (GB10) and 20% (GB20), substituting for wheat flour. Phenolic compounds, antioxidant capacity, volatile compounds profile, and sensory acceptability of control bread (CB; without GP) and guava breads (GB) were evaluated. Incorporation of GP increased roughly 2-to-3-fold the phenolic compounds contents of bread. Ten phenolic compounds were identified in GB20, and quercetin-3-O-rutinoside was the major compound, while in CB, ferulic acid was the major among the six phenolic compounds in CB. Bread making seemed to promote the release of phenolic compounds from structural components. Breads incorporated with GP presented a richer volatile profile than CB, especially due to the presence of terpenes. GB improved aroma profile of bread. GP added aroma compounds and phenolic antioxidants, and seemed to be an interesting approach to enhance bread bioactivity and acceptability.

Pomegranate peel and peel extracts: chemistry and food features

The present review focuses on the nutritional, functional and anti-infective properties of pomegranate (Punica granatum L.) peel (PoP) and peel extract (PoPx) and on their applications as food additives, functional food ingredients or biologically active components in nutraceutical preparations. Due to their well-known ethnomedical relevance and chemical features, the biomolecules available in PoP and PoPx have been proposed, for instance, as substitutes of synthetic food additives, as nutraceuticals and chemopreventive agents. However, because of their astringency and anti-nutritional properties, PoP and PoPx are not yet considered as ingredients of choice in food systems. Indeed, considering the prospects related to both their health promoting activity and chemical features, the nutritional and nutraceutical potential of PoP and PoPx seems to be still underestimated. The present review meticulously covers the wide range of actual and possible applications (food preservatives, stabilizers, supplements, prebiotics and quality enhancers) of PoP and PoPx components in various food products. Given the overall properties of PoP and PoPx, further investigations in toxicological and sensory aspects of PoP and PoPx should be encouraged to fully exploit the health promoting and technical/economic potential of these waste materials as food supplements.

Effect of pomegranate peel supplementation on nutritional, organoleptic and stability properties of cookies

The present study aims at highlighting the nutritive potential of pomegranate peel and its possible utilization as an ingredient of choice to nutritionally enrich cookies. Biochemical composition and free radical scavenging features of pomegranate peel powder (PoP) and PoP supplemented cookies were measured. PoP supplementation significantly (p < 0.05) improved dietary fibers (0.32-1.96 g/100 g), total phenols (90.7-161.9 mg GAE/100 g) and inorganic residues (0.53-0.76 g/100 g) of cookies. Similarly, significant increase in Ca, K, Fe and Zn levels was noted in supplemented cookies. Almost 50% 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was recorded in cookies carrying highest concentration of PoP and phenolic contents. PoP phenolics of supplemented cookies were shown to reduce oxidative degradation during four months storage. Present study suggests PoP supplementation in baked products as a potential source of micro and macronutrients. Application of PoP in ready to serve foods seems to be a potential disease preventive and ameliorative approach in tandem with its preservation and nutritional enhancement features.