Optimisation of granola breakfast cereal manufacturing process by wet granulation and pneumatic conveying

This study has considered the optimisation of granola breakfast cereal manufacturing processes by wet granulation and pneumatic conveying. Granola is an aggregated food product used as a breakfast cereal and in cereal bars. Processing of granola involves mixing the dry ingredients (typically oats, nuts, etc.) followed by the addition of a binder which can contain honey, water and/or oil. In this work, the design and operation of two parallel wet granulation processes to produce aggregate granola products were incorporated: a) a high shear mixing granulation process followed by drying/toasting in an oven. b) a continuous fluidised bed followed by drying/toasting in an oven. In high shear granulation the influence of process parameters on key granule aggregate quality attributes such as granule size distribution and textural properties of granola were investigated. The experimental results show that the impeller rotational speed is the single most important process parameter which influences granola physical and textural properties. After that binder addition rate and wet massing time also show significant impacts on granule properties. Increasing the impeller speed and wet massing time increases the median granule size while also presenting a positive correlation with density. The combination of high impeller speed and low binder addition rate resulted in granules with the highest levels of hardness and crispness. In the fluidised bed granulation process the effect of nozzle air pressure and binder spray rate on key aggregate quality attributes were studied. The experimental results show that a decrease in nozzle air pressure leads to larger in mean granule size. The combination of lowest nozzle air pressure and lowest binder spray rate results in granules with the highest levels of hardness and crispness. Overall, the high shear granulation process led to larger, denser, less porous and stronger (less likely to break) aggregates than the fluidised bed process. The study also examined the particle breakage of granola during pneumatic conveying produced by both the high shear granulation and the fluidised bed granulation process. Products were pneumatically conveyed in a purpose built conveying rig designed to mimic product conveying and packaging. Three different conveying rig configurations were employed; a straight pipe, a rig consisting two 45° bends and one with 90° bend. Particle breakage increases with applied pressure drop, and a 90° bend pipe results in more attrition for all conveying velocities relative to other pipe geometry. Additionally for the granules produced in the high shear granulator; those produced at the highest impeller speed, while being the largest also have the lowest levels of proportional breakage while smaller granules produced at the lowest impeller speed have the highest levels of breakage. This effect clearly shows the importance of shear history (during granule production) on breakage during subsequent processing. In terms of the fluidised bed granulation, there was no single operating parameter that was deemed to have a significant effect on breakage during subsequent conveying. Finally, a simple power law breakage model based on process input parameters was developed for both manufacturing processes. It was found suitable for predicting the breakage of granola breakfast cereal at various applied air velocities using a number of pipe configurations, taking into account shear histories

Benefits of Value Addition in Agricultural Produce on Land, Water and Labor Productivities under Arid Agriculture: Case of Dates in Oman

Oman is an arid country in the Middle East with water scarcity, and hence land and labor management issues hindering agricultural sustainability and food security. Value addition can minimize food wastes, which is crucial to achieve sustainability by improving the land, water and labor productiveness. This study aimed to evaluate and quantify the improvements in land, water and labor productivities through value addition in date cultivated under arid conditions in Oman. Five date factories and different value-added products of the most popular date varieties, Khalas and Fardh were selected for this study. The comparisons were made between productivity improvements of the value-added products and the raw products. Khalas dates value-added with nuts had the highest productivity ratio of 540%, the same for Fardh was 360% while the lowest were in Khalas value-added with flavors with 111% and in Fardh date paste with 129%. In Khalas, the best improvement by the value addition in average land, water and labor productivities from the base-values of 6.93 ton ha-1, 0.57 kg m-3, and 0.82 kg h-1 of the raw date were 25.05 ton ha-1, 2.06 kg m-3, and 2.95 kg h-1 in date with nuts, respectively; while in the Fardh, these were 18.82 ton h-1, 1.55 kg m-3, and 2.21 kg h-1 respectively of the same value-added product. The variations in productivity improvement of selected value-added products could be due to the availability and cost of the raw dates, cost of the value addition, market options and selling price. Value addition showed high potential for improving productivities under arid conditions and is worth making adoption efforts for achieving agricultural sustainability goals

Optimization of drying parameters for pretreated green banana slices using response surface methodology

In this study, the influence of drying temperature and pretreatment on the drying kinetics and quality metrics of green banana slices was investigated. The present investigation included the drying of 4 ± 1 mm green banana slices with potassium metabisulfite (KMS) at levels of 0 (control), 0.5%, 1%, and 1.5% in a tray dryer. A numerical optimization method was utilized to optimize the drying rate, color, water activity, rehydration ratio, and attractiveness of the banana slices, using a variety of input factors such as drying temperature and pretreatment. The results revealed that the untreated samples and those treated with 1.0% and 1.5% KMS required a longer drying time than the samples treated with 0.5% KMS. The process parameters were optimized using response surface methodology, adopting an I‐optimal design for this investigation. The best solution yielded a drying air temperature of 60.62°C and a pretreatment level of 0.786% KMS, resulting in a drying time of 346.28 min, a color (L∗) value of 76.23, a water activity (aw) of 0.299, and a rehydration ratio of 2.81. Similar outcomes were obtained when the optimized conditions were tested and compared with experimental data using an experimental validation process.Journal of Food Qualit

Design of Packaging Vents for Cooling Fresh Horticultural Produce

Abstract This review focuses on the design of vents in packages used for handling horticulture produce. The studies on vent designs that are conducted to obtain fundamental understanding of the mechanisms by which different parameters affect the rate and homogeneity of the airflow and the cooling process are presented. Ventilated packages should be designed in such a way that they can provide a uniform airflow distribution and consequently uniform produce cooling. Total opening area and opening size and position show a significant effect on pressure drop, air distribution uniformity and cooling efficiency. Recent advances in measurement and mathematical modelling techniques have provided powerful tools to develop detailed investigations of local airflow rate and heat and mass transfer processes within complex packaging structures. The complexity of the physical structure of the packed systems and the biological variability of the produce make both experimental and model-based studies of transport processes challenging. In many of the available mathematical models, the packed structure is assumed as a porous medium; the limitations of the porous media approach are evident during vented package design studies principally when the containerto-produce dimension ratio is below a certain value. The complex and chaotic structure within horticultural produce ventilated packages during a forced-air precooling process complicates the numerical study of energy and mass transfer considering each individual produce. Future research efforts should be directed to detailed models of the vented package, the complex produce stacking within the package, as well as their interaction with adjacent produce, stacks and surrounding environment. For the validation of the numerical models, the development of better experimental techniques taking into account the complex packaging system is also very important

Physiological Response of Stored Pomegranate Fruit Affected by Simulated Impact

Mechanical damage resulting from excessive impact force during handling and other postharvest operations from harvesting to consumption is a critical quality problem in fresh produce marketing. The study investigates the impact of bruise damage, storage temperature, and storage period on the physiological responses of Omani pomegranate fruit cultivar ‘Helow’. Fruits were subjected to low (45°; 1.18 J) and high (65°; 2.29 J) impact levels using a pendulum test by hitting the fruit on the cheek side. Bruised and non-bruised fruit were stored at 5 and 22 °C for 28 days. Bruise measurements, water loss per unit mass, water loss per surface area, firmness, fruit size measurements, geometric mean diameter, surface area, fruit volume, color parameters, respiration rate, and ethylene production rate were evaluated. Bruise area, bruise volume, and bruise susceptibility of damaged pomegranate fruit were increased as impact level, storage duration, and storage temperature increased. Pomegranates damaged at a high impact level and conditioned at 22 °C showed 20.39% weight loss on the last day of storage compared to the control and low-impact-bruised fruit. Firmness and geometric mean diameter were significantly (p < 0.05) reduced by bruising at a high impact level. Impact bruising level and storage temperature decreased lightness, yellowness, browning index, and increased redness over time. Furthermore, the respiration rate was five times higher in the non-bruised and low- and high-impact-injured fruit stored at 22 °C than that stored at 5 °C. The ethylene production rate recorded its highest value on day 21 in high-level-impact-bruised pomegranate fruit. The bruise susceptibility was strongly correlated with the majority of the studied parameters. This study can confirm that bruising can affect not only the visual quality characteristics but also the physiological attributes of pomegranate fruit; therefore, much care is required to preserve fresh produce and avoid any mechanical damage and losses during postharvest handling

Effect of Simulated Vibration and Storage on Quality of Tomato

The influence of simulated transport vibration and storage conditions for 10 days on tomato fruits quality (color, weight, firmness, total soluble solids, and headspace gases) were investigated. Better kinetic models for color changes, weight loss, and firmness of stored tomato fruits were selected. Tomato fruits were divided equally into two main groups where the first one was subjected to vibration at a frequency of 2.5 Hz for two hours and the other group was set as a control (with no vibration stress). Both tomato groups were stored for 10 days at 10 °C and 22 °C storage conditions. The results showed a reduction in total soluble solids, yellowness, weight, lightness in the tomato fruits subjected to vibration at 22 °C storage condition. Ethylene and carbon dioxide increased by 124.13% and 83.85% respectively on the same condition (22 °C). However, storage at 10 °C slowed down the investigated quality changes attributes of both tomato groups (vibrated and control) during storage. The weight loss change kinetics of both tomato groups at both storage temperatures were highly fitted with a zero-order kinetic model. Color and firmness kinetic changes of tomato groups stored at both conditions were described well by zero and first order kinetic models. To validate the appropriateness of the selected model, lightness, redness, yellowness, and firmness were taken as an example. The study revealed that the vibration occurrence and increasing storage temperature cause various changes in the quality attributes of tomatoes

Kinetic modeling of quality changes of tomato during storage

Quality deterioration in tomato along the supply chain due to postharvest losses has become a continual challenge in Middle East countries. The aim of this study is to determine the changes in tomato quality parameters during storage. Fresh tomatoes were purchased from the Central Market of Fruits and Vegetables and stored at 10oC and 22oC for 12 days to assess color, weight loss, firmness and TSS parameters. Statistical analysis like (R2, X2, SE and RMSE) and ANOVA were performed using SPSS software. Experimental results showed a high significant impact (p < 0.05) in tomato quality parameters such as color, firmness and weight loss stored at 22oC. Storage at 22oC had a rapid alteration of a* and L* parameters to the darker region.  A slow increase on weight loss, a*, CI, COL and ∆E were observed with less decrease on L* and firmness during the exposure to 10°C storage. The appropriate model to demonstrate the color change was the first-order model. However, firmness was described by the zero-order model. Zero-order and first-order models used to describe quality changes during storage. Overall, tomato stored at 10°C provided a desired results of firmness, weight loss and color change compared to tomato stored at 22°C

Technological Advancements in Food Processing and Packaging

The global challenge of providing sufficient, safe, and sustainable food to a growing population requires continuous food processing and packaging technology advancements [...

Effect of mechanical damage on the quality characteristics of banana fruits during short-term storage

AbstractFresh fruits like bananas are very susceptible to mechanical damage during postharvest handling which can result in a substantial decline in quality. The study aims to evaluate the effect of bruise damage and storage temperatures on the quality of banana fruits after 48 h storage. Each ‘Grand Naine’ banana fruit was impacted once by using a drop impact test using three different heights (10, 30, and 50 cm) and storage temperatures (13 and 22 °C) after 48 h of storage. Different quality analyses were measured like bruise measurements (impact energy, bruise area, bruise volume, and bruise susceptibility), weight loss, total soluble solids (TSS), color (L*, a*, b*, hue°, chroma, yellowness index, yellowness value) headspace gases (respiration and ethylene production rate). The results showed that bruise measurements (bruise area, bruise volume, and bruise susceptibility) were highly affected by drop height. The quality parameters like weight, color, total soluble solids and headspace gases were affected by drop height and storage condition. Weight loss, total soluble solids, respiration rate, and ethylene production rate increased as drop height and storage temperature rise. Storage at ambient conditions (22 °C) accelerated bruising occurrence in banana fruits. Fewer changes were observed after 48 h of storage. The least value of yellowness index was observed on the non-bruised banana fruits (84.03) under 13 °C storage conditions. The findings of the study can provide baseline data to understand the mechanical damage mechanism on fruit quality, hoping to create awareness and educate farming communities and consumers. Storage temperature management is another approach that needs to be followed to reduce the occurrence of mechanical damage in fresh produce.</jats:p