Drying of Garlic Slices Using Convective Pre-drying and Vacuum-Microwave Finishing Drying: Kinetics, Energy Consumption, and Quality Studies

The nutritional value, bioactive availability and functional properties of garlic and its related products during processing

Garlic, a common culinary spice, is cultivated and used around the globe. Consumption of garlic and its supplements reduces the risk of diabetes and cardiovascular disease and boosts the immune system with antibacterial, antifungal, anti-aging, and anti-cancer properties. Diallyl sulfide, diallyl disulfide, triallyl trisulfide, phenolics, flavonoids, and others are the most commercially recognized active ingredients in garlic and its products. In recent years, global demand for medicinal or functional garlic has surged, introducing several products such as garlic oil, aged garlic, black garlic, and inulin into the market. Garlic processing has been demonstrated to directly impact the availability of bioactive ingredients and the functionality of products. Depending on the anticipated functional qualities, it is also recommended that one or a combination of processing techniques be deemed desirable over the others. This work describes the steps involved in processing fresh garlic into products and their physicochemical alterations during processing. Their nutritional, phytochemical, and functional properties are also reviewed. Considering the high demand for functional food, this review has been compiled to provide guidance for food producers on the industrial utilization and suitability of garlic for new product development.

Effect of dielectric barrier discharge (DBD) cold plasma-activated water pre-treatment on the drying properties, kinetic parameters, and physicochemical and functional properties of Centella asiatica leaves

Centella asiatica L. (CA) is a medicinal plant that gained significant commercial and research interest because of its bioactive compounds, which have functional properties such as antioxidant activity. However, it must be dried before use to improve its shelf life and prepare it for food and pharmaceutical applications. Therefore, in this investigation CA leaves were pre-treated with blanching and cold plasma activated water (CPAW), followed by recirculatory hot air and vacuum drying at 40, 50, and 60 °C. Vacuum-drying took 150-720 min, while hot-air drying took 60-180 min to dry. Page and Logarithmic models best fit for leaf drying kinetics, according to AIC, with R² between 0.966 and 0.999 and RMSE between 0.001 and 0.069. CPAW pre-treatment increased leaf quality more than blanching in vacuum drying. Drying leaves at 40 °C boosted antioxidants (4021.462 μg TE (g dw)^-1 and 3.356 mg GAEAC (g dw)^-1), TPC (35.049 mg GAE (g dw)^-1), and TFC (311.274 mg QE (g dw)^-1) and is recommended. Vacuum-drying with CPAW pre-treatment preserved leaf microstructure better than hot-air drying. This study illuminates CA leaf drying behaviour and allow mass production without damaging bioactive components. These results could be used as a roadmap for future technological advances that will make it possible to use the bioactive components of CA in food formulation.

The Effect of Nonthermal Pretreatment on the Drying Kinetics and Quality of Black Garlic

Black garlic is obtained from regular garlic (Allium sativum L.) through the aging process and consequently gains many health-promoting properties, including antidiabetic and antioxidant. However, the material is still prone to microbiological deterioration and requires a long time to dry due to its properties. Therefore, this study aimed to investigate the effect of various drying methods on the quality of black garlic as well as determine the influence of selected nonthermal pretreatments on the drying kinetics and quality of black garlic, which is especially important in the case of the materials that are difficult to dry. The Weibull model was chosen to describe drying kinetics. Additionally, color, water activity together with antioxidant activity, phenolic compounds, and antidiabetic potential were determined. This study found that the application of a pulsed electric field (PEF), a constant electric field (CEF) as well as a magnetic field (MF) significantly reduced the time of drying (by 32, 40, and 24 min for a PEF, a CEF, and a MF, respectively, compared to combined drying without the pretreatment), and resulted in high antidiabetic potential. However, the highest content of phenolic compounds (1123.54 and 1125.36 mg/100 g dm for VMD125 and CD3h-VMD, respectively) and antioxidant capacity (ABTS = 6.05 and 5.06 mmol Trolox/100 g dm for VMD500 and CD6h-VMD, respectively) were reported for black garlic treated by vacuum-microwave drying and combined convective pre-drying followed by vacuum-microwave drying. Overall, the nonthermal pretreatment decreased the time of drying and showed very good efficiency in maintaining the antidiabetic potential of black garlic, especially in the case of the materials pretreated by a constant electric field (IC₅₀ = 99 and 56 mg/mL, for α-amylase and α-glucosidase, respectively).

Microstructure Analysis and Quality Evaluation of Jujube Slices Dried by Hot Air Combined with Radio Frequency Heat Treatment at Different Drying Stages

Jujubes have been favored by consumers because of their rich nutrition and wide use. Hot air drying has been commercially and typically used to prolong shelf life and acquire the dried produce. Jujube slices were dried with hot air combined with radio frequency (RF) at different drying stages, namely, early (0–2 h, E-HA + RF), middle (2–4 h, M-HA + RF), later (4–6 h, L-HA + RF), and whole (0–6 h, W-HA + RF) stages. This study aimed to investigate the effects of different RF application stages on the microstructure, moisture absorption rate, color, and ascorbic acid of jujube slices. Compared with the hot air drying (HA) group, the E-HA + RF group obtained the best results among the experimental groups because it reduced the cells with a roundness of less than 0.4 by 5%. Moreover, the M-HA + RF group showed better results than those of other groups, with an 18.6% and 48.8% reduction in cells for a cross-sectional area less than 200 µm² and a perimeter less than 25 µm, respectively. The minimum total color difference (ΔE = 9.21 ± 0.31) and maximum retention of ascorbic acid (285.06 mg/100 g) were also observed in this group. Therefore, the method of hot air drying assisted by phased RF is viable in the drying industry to improve the quality of dried agricultural products and reduce energy consumption.

The retention and bioavailability of phytochemicals in the manufacturing of baked snacks

There is a growing body of evidence supporting the role that phytochemicals play in reducing the risk of various chronic diseases. Although there has been a rise in health products marketed as being "supergrains," "superfood," or advertising their abundance in antioxidants, these food items are often limited to powdered blends, dried fruit, nuts, or seeds, rarely intercepting the market of baked snacks. This is in part due to the still limited understanding of the impact that different industrial processes have on phytochemicals in a complex food matrix and their corresponding bioavailability. This review brings together the current data on how various industrial dehydration processes influence the retention and bioaccessibility of phytochemicals in baked snacks. It considers the interplay of molecules in an intricate snack matrix, limitations of conventional technologies, and constraints with consumer acceptance preventing wider utilization of novel technologies. Furthermore, the review takes a holistic approach, encompassing each stage of production-discussing the potential for inclusion of by-products to promote a circular economy and the proposal for a shift in agriculture toward biofortification or tailored growing of crops for their nutritional and post-harvest attributes.

Effect of Filtrated Osmotic Solution Based on Concentrated Chokeberry Juice and Mint Extract on the Drying Kinetics, Energy Consumption and Physicochemical Properties of Dried Apples

BACKGROUND

Filtration of osmotic solution affects selective penetration during osmotic dehydration (OD), and after drying is finished, this can influence the chemical composition of the material, which is also modified by OD.

METHODS

Osmotic dehydration was carried out in filtrated and non-filtrated concentrated chokeberry juice with the addition of mint infusion. Then, this underwent convective drying, vacuum-microwave drying and combined convective pre-drying, followed by vacuum-microwave finishing drying. Drying kinetics were presented and mathematical models were selected. The specific energy consumption for each drying method was calculated and the energy efficiency was determined.

RESULTS AND DISCUSSION

The study revealed that filtration of osmotic solution did not have significant effect on drying kinetics; however, it affected selective penetration during OD. The highest specific energy consumption was obtained for the samples treated by convective drying (CD) (around 170 kJ·g-1 fresh weight (fw)) and the lowest for the samples treated by vacuum-microwave drying (VMD) (around 30 kJ·g-1 fw), which is due to the differences in the time of drying and when these methods are applied.

CONCLUSIONS

Filtration of the osmotic solution can be used to obtain the desired material after drying and the VMD method is the most appropriate considering both phenolic acid content and the energy aspect of drying.

Effects of Different Drying Methods on the Retention of Bioactive Compounds, On-Line Antioxidant Capacity and Color of the Novel Snack from Red-Fleshed Apples

The aim of this study was to determine the effect of different drying methods: convective (at 50, 60, 70 °C), vacuum-microwave (at 120, 240, 360, 480 W and 360 W with reduction to 120 W) and hybrid (convective pre-drying at 50, 60, 70 °C followed by vacuum-microwave drying at 120 W) on the quality parameters of novel red-fleshed apple fruit snacks (RFAs), such as phenolics, on-line antioxidant capacity, water activity and color. Drying kinetics, including a temperature profile of dried material, and modified Page model were determined. Freeze-drying was used as a control method. The highest content of bioactive compounds in the samples was retained following freeze-drying, then hybrid, vacuum-microwave and finally convection drying. The antioxidant capacity measured by on-line 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), identified anthocyanins, flavan-3-ols and phenolic acid as the main compounds responsible for this activity. Unfavorable changes in color, formation of hydroxymethylfurfural (HMF) and degradation of polyphenolics were noted along with increasing drying temperature and magnetron power. The red-fleshed apple snacks are a promising high-quality dehydrated food product belonging to functional foods category.

Role of drying techniques on physical, rehydration, flavor, bioactive compounds and antioxidant characteristics of garlic

Various drying techniques play an important role in foodstuff preservation. However, the role of different drying techniques on garlic quality is limited. The purpose of this study was to investigate the effect of vacuum freeze-drying (VFD), hot air drying (HAD), infrared hot air drying (IRHAD), relative humidity drying (RHD) and pulsed vacuum drying (PVD) on the physical, rehydration, flavor, bioactive compounds and antioxidant characteristics of garlic slices. Results showed that garlic slices treated with VFD had an attractive color, low shrinkage, low hardness, and the lowest rehydration capacity. The volume shrinkage ratio, thermal stability and storage stability of garlic slices after HAD were the highest. Different dried garlic samples had different specific flavor fingerprints. IRHAD and RHD dried samples showed the highest rehydration capacity, content of bioactive compounds and antioxidant activity. The findings could provide a scientific basis to help in future large-scale production of good quality dried garlic products.

Volatile Composition and Sensory Properties as Quality Attributes of Fresh and Dried Hemp Flowers (Cannabis sativa L.)

Flowers of hemp (Cannabis sativa L.) are widely used in cosmetics, food, and in the pharmaceutical industry. The drying process plays a key role in retention of aroma and also in the quality of products. Seven variants of hemp flower drying, including convection drying (CD), vacuum–microwave drying (VMD), and combined drying consisting of convective pre-drying followed by vacuum–microwave finishing drying (CPD-VMFD) were checked in this study. For each process, we applied the two-term model. Dried material was submitted to color and chromatographical assessments. Analyses of obtained essential oil showed the presence of 93 volatile compounds, predominantly β-myrcene, limonene, and β-(E)-caryophyllene, as well as α-humulene. Application of 240 W during VMD and 50 °C during CD gave the highest retention of aroma compounds, amounting to 85 and 76%, respectively, but with huge color changes. Additionally, sensory analysis proved that drying with a microwave power of 240 W provides a product most similar to fresh material.

Hybrid Drying of Murraya koenigii Leaves: Energy Consumption, Antioxidant Capacity, Profiling of Volatile Compounds and Quality Studies

This study aims to reduce the amount of specific energy consumed during the drying of fresh Murraya koenigii leaves by comparing four drying methods: (1) convective hot-air drying (CD; 40, 50 and 60 °C); (2) single-stage microwave-vacuum drying (MVD; 6, 9 and 12 W/g); (3) two-stage convective hot-air pre-drying followed by microwave-vacuum finishing–drying (CPD-MVFD; 50 °C, 9 W/g); and (4) freeze-drying as a control in the analysis sections. The drying kinetics were also modelled using thin-layer models. The quality parameters of dried M. koenigii leaves were measured including total polyphenolic content (TPC), antioxidant capacity (ABTS and FRAP), profiling of volatile compounds, colour analysis and water activity analysis. Results showed that CPD-MVFD effectively reduced the specific energy consumption of CD at 50 °C by 67.3% in terms of kilojoules per gram of fresh weight and 48.9% in terms of kilojoules per gram of water. The modified Page model demonstrated excellent fitting to the empirical data obtained. FD showed promising antioxidant activity. The major contributor of antioxidant capacity was TPC. The volatile compounds profiled by gas chromatography-mass spectrometry, namely, β-phellandrene (31%), α-pinene (19.9%), and sabinene (16%) were identified as the major compounds of dried M. koenigii leaves. Colour analysis showed MVD’s high performance in preserving the colour parameters of M. koenigii leaves under all conditions. The colour parameters were correlated to the antioxidant capacity and TPC. Water activity analysis showed that the water activity of M. koenigii leaves for all drying methods indicating that the conditions were microbiologically and shelf-stable. Pearson correlation showed the colour parameters of the leaves had a strong correlation to TPC. Overall, MVD showed promising energy consumption reduction and recovery in TPC and volatile compounds.

Determination of Various Drying Methods' Impact on Odour Quality of True Lavender (Lavandula angustifolia Mill.) Flowers

True lavender flowers (Lavandula angustifolia Mill.) is a critical source of essential oils and a flavouring agent used in numerous industries like foods, cosmetics and pharmaceuticals. Its main volatile constituents are linalool and linalyl acetate, which are commonly considered as main odour-active constituents (OACs). Nevertheless, the quality of true lavender flowers is highly dependent on its post-harvest treatment, mainly the preservation method. Recognising that drying is the most frequently used preservation method, the influence of various drying methods, including convective drying (CD) at 50, 60 and 70 °C, vacuum-microwave drying (VMD) with powers 240, 360 and 480 W and combined convective pre-drying at 60 °C followed by vacuum-microwave finish-drying with power 480 W (CPD-VMFD), on the quality of true lavender flowers was verified. The evaluation of influence was carried out by HS-SPME(HS, solid-phase microextraction), GC-MS, GC-MS-O (gas chromatography–mass spectrometry–olfactometry) techniques. Moreover, the sensory panel has assessed the sample odour quality. As a result, the optimal drying methods regarding the requirements for products were established. Overall, for total essential oil recovery, CD at 50 °C is the optimal drying method, while for odour quality concerning the sensory panel evaluation, VMD with power 360 W combined CPD-VMFD and CD at 50 °C is the optimal drying method.

Review of recent applications and research progress in hybrid and combined microwave-assisted drying of food products: Quality properties

The growing concerns over product quality have increased demand for high quality dried food products and encouraged researchers to explore and producers of such products to implement novel microwave (MW)-assisted drying methods. This paper presents a critical review of the key principles and drawbacks of MW-assisted drying as well as needs for future research. In this article, recent research into application of microwaves as an alternative heat source, applications and progress in hybrid MW-assisted drying that rely on various drying media and combined two or three stages of MW-assisted drying for the preservation of food products is reviewed critically. The effect of different MW-assisted drying methods, conditions and initial pretreatments on the thermophysical properties, color, nutritional value and rehydration potential of dried food products is discussed in detail along with the discussion on how the material properties evolve and change in structure, color, and composition during MW-assisted drying and recent attempts at mathematical modeling of these changes made for different fruits and vegetables. It should be noted that most of the published results were obtained in laboratory-scale dryers. Pilot-scale testing is needed to bridge the gap between laboratory research and industrial applications to fulfill the potential for novel hybrid and combined MW-assisted drying methods and to expand their role in food processing.

Influence of Different Drying Techniques on Phenolic Compounds, Antioxidant Capacity and Colour of Ziziphus jujube Mill. Fruits

This study was to present the effect of different parameters of combined methods of drying such as vacuum-microwave (VMD: 480, 120 W), hot air (CDD: 70, 60, 50 °C) and combined methods as pre-drying by CD and finish drying by VMD (CD-VMD: 60 °C + 480/120W) in order to avoid a rapid increase in temperature at the critical moisture content of ca. 1 kg/kg dm (dry mass). Control samples were prepared by freeze-drying (FD). Drying kinetics, including the temperature profile of dried material, as well as on some quality factors of the finished product as phenolic compounds, antioxidant capacity, and color were evaluated. The increase in air temperature during CD as well as the increase in material temperature during VMD deteriorated dried product quality in terms of the content of phenolic compounds, antioxidant activity and color. Dried jujube fruits have a long shelf life and therefore may be a fine alternative to fresh fruit all year round.

Characterisation of the Convective Hot-Air Drying and Vacuum Microwave Drying of Cassia alata: Antioxidant Activity, Essential Oil Volatile Composition and Quality Studies

The preservation of active constituents in Cassia alata through the removal of moisture is crucial in producing a final product with high antioxidant activity. This study aims to determine the influences of various drying methods and drying conditions on the antioxidant activity, volatiles and phytosterols content of C. alata. The drying methods used were convective drying (CD) at 40 °C, 50 °C and 60 °C; freeze drying; vacuum microwave drying (VMD) at 6, 9 and 12 W/g; and two-stage convective pre-drying followed by vacuum microwave finish drying (CPD-VMFD) at 50 °C and 9 W/g. The drying kinetics of C. alata are best described by the thin-layer model (modified Page model). The highest antioxidant activity, TPC and volatile concentration were achieved with CD at 40 °C. GC–MS analysis identified the presence of 51 volatiles, which were mostly present in all samples but with quantitative variation. The dominant volatiles in fresh C. alata are 2-hexenal (60.28 mg 100 g⁻¹ db), 1-hexanol (18.70 mg 100 g⁻¹ db) and salicylic acid (15.05 mg 100 g⁻¹ db). The concentration of phytosterols in fresh sample was 3647.48 mg 100 g⁻¹ db, and the major phytosterols present in fresh and dried samples were β-sitosterol (1162.24 mg 100 g⁻¹ db). CPD-VMFD was effective in ensuring the preservation of higher phytosterol content in comparison with CD at 50 °C. The final recommendation of a suitable drying method to dehydrate C. alata leaves is CD at 40 °C.

Drying of Phyla nodiflora Leaves: Antioxidant Activity, Volatile and Phytosterol Content, Energy Consumption, and Quality Studies

Drying is an important process in the preservation of antioxidants in medicinal plants. In this study, leaves of Phyla nodiflora, or commonly known as frog fruit, were dried using convective drying (CD) at 40, 50, and 60 °C; vacuum-microwave drying (VMD) at 6, 9, and 12 W/g; and convective pre-drying followed by vacuum-microwave finish drying (CPD–VMFD) at 50 °C and 9 W/g. Drying kinetics of P. nodiflora leaves was modelled, and the influences of drying methods on the antioxidant activity, total phenolic content, volatile and phytosterol contents, energy consumption, water activity, and color properties were determined. Results showed that drying kinetics was best described by modified Page model. VMD achieved highest drying rate, whereas VMFD considerably reduced the drying time of CD from 240 min to 105 min. CPD–VMFD was the best option to dry P. nodiflora in terms of retaining volatiles and phytosterols, with lower energy consumption than CD. Meanwhile, VMD at 6 W/g produced samples with the highest antioxidant activity with 2,2′-Azinobis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) value of 11.00 and 15.99 µM Trolox/100 g dw, respectively.

A comprehensive analysis and comparison between vacuum and electric oven drying methods on Chinese saffron (Crocus sativus L.)

The red stigmas of saffron are one of the most expensive spices in the world and serve as a traditional Chinese medicine. More saffron has been cultivated in China, and different drying technologies have been studied. However, a comprehensive and comparative analysis of different drying approaches has not been well studied. In this study, we compared electric oven and vacuum oven drying approaches on saffron. We found saffron was dried quicker under high vacuum drying mode with high temperature and the quicker drying rate provided, the more open microstructural interstices on the saffron surface. Both methods were best fit to Midilli and Kucuk model. Besides, the coloring, aroma and bitterness strength after drying showed the similar results. In sum, our data suggested the optimal drying temperature was 100 °C for 20 min for two evaluated methods, however considering the machine cost, the electric oven drying would be the first choice.

The effect of drying methods on the energy consumption, bioactive potential and colour of dried leaves of Pink Rock Rose (Cistus creticus)

This study aimed to investigate the changes in the total polyphenolic content and antioxidant properties after subjecting Pink Rock Rose (Cistus creticus) leaves to three different drying procedures, including convection drying (CD) at 40, 50 and 60 °C; vacuum-microwave drying (VMD) at 240 W microwave power; and combined drying consisting of convective pre-drying at 50 °C followed by vacuum-microwave finish drying at 240 W microwave power (CPD-VMFD). The total polyphenolic content and antioxidant properties (DPPH, ABTS) of leaves subjected to these three drying methods were spectrophotometrically determined. The results show that convection drying at 40 °C and vacuum-microwave drying yielded dried leaves with the highest bioactive potential in terms of the total polyphenol content and antioxidant activity, with the highest and lowest values of final specific energy consumption, respectively. The lowest bioactive potential was found in a product dried at 60 °C, which can be attributed to the possible degradation or changes in polyphenol structures under high temperatures. During the combined treatment (CPD-VMFD), most of the moisture was efficiently removed from the raw material by CPD, whereas the time of drying was significantly reduced by the application of VMFD. Combined drying CPD-VMFD is most suitable for industrial applications as it produces dried leaves with a bioactive potential that is only slightly lower than that achieved with VMD while providing a high-throughput capacity relative to operating costs.

HS-SPME Analysis of True Lavender (Lavandula angustifolia Mill.) Leaves Treated by Various Drying Methods

True lavender (Lavandula angustifolia Mill.) is a widely used flavoring and medicinal plant, which strong aroma is mainly composed of linalool and linalyl acetate. The most valuable parts of the plant are the flowers, however leaves are also abundant in volatile constituents. One of the main factors responsible for its quality is the preservation procedure, which usually comes down to a drying process. For this reason an attempt to verify the influence of various drying methods (convective drying, vacuum-microwave drying and combined convection pre-drying with vacuum-microwave finishing drying) on the quality of true lavender leaves was carried out by determination of the volatile constituents profile by solid-phase microextraction (SPME) coupled with GC-MS technique. Total essential oil (EO) content was also verified. The study has revealed that the optimal drying method is strongly dependent on the purpose of the product. For flavoring properties convective drying at 60 °C is the most optimal method, while the best for preserving the highest amount of EO is vacuum-microwave drying at 480 W. Furthermore, SPME analysis had shown that drying may increase the value of true lavender leaves by significantly affecting the linalool to linalyl acetate to camphor ratio in the volatile profile.

The Influence of Drying Method on Volatile Composition and Sensory Profile of Boletus edulis

The objective of this study was to evaluate the influence of different drying methods on aroma and sensory profile of Boletus edulis (cepe). The drying methods tested were convective drying (CD), freeze-drying (FD), vacuum microwave drying (VMD), and a combination of convective predrying and vacuum microwave finish-drying (CPD-VMFD). Fresh and dried cepe volatiles, analyzed by SPME and GC-MS, showed the presence of 53 volatile compounds, most of them present in all dried samples but with quantitative variation. The major volatile compounds in fresh and dried cepe were 1-octen-3-ol (3405 µg 100 g−1·db), 3-octanone (429 µg 100 g−1·db), and hexanal (355 µg 100 g−1·db). The results showed that drying of cepe mushrooms caused major losses of aroma compounds; however, the highest content of volatile compounds and the highest intensity of most of the key positive sensory attributes were found in samples after (i) CD at 80°C (3763 µg 100 g−1·db), (ii) CD at 70°C (3478 µg 100 g−1·db), and (iii) CPD at 60°C and VMFD at 480/240 W (2897 µg 100 g−1·db).

Overall Quality of Fruits and Vegetables Products Affected by the Drying Processes with the Assistance of Vacuum-Microwaves

The seasonality of fruits and vegetables makes it impossible to consume and use them throughout the year, thus numerous processing efforts have been made to offer an alternative to their fresh consumption and application. To prolong their availability on the market, drying has received special attention as currently this method is considered one of the most common ways for obtaining food and pharmaceutical products from natural sources. This paper demonstrates the weakness of common drying methods applied for fruits and vegetables and the possible ways to improve the quality using different drying techniques or their combination with an emphasis on the microwave energy. Particular attention has been drawn to the combined drying with the assistance of vacuum-microwaves. The quality of the dried products was ascribed by chemical properties including the content of polyphenols, antioxidant capacity and volatiles as well as physical parameters such as color, shrinkage, porosity and texture. Both these fields of quality classification were considered taking into account sensory attributes and energy aspects in the perspective of possible industrial applications. In conclusion, the most promising way for improving the quality of dried fruit and vegetable products is hybrid drying consisting of osmotic dehydration in concentrated fruit juices followed by heat pump drying and vacuum-microwave finish drying.

Research developments in methods to reduce the carbon footprint of the food system: a review

Global warming is a worldwide issue with its evident impact across a wide range of systems and sectors. It is caused by a number of greenhouse gases (GHGs) emissions, in which food system has made up of a large part. Recently, reduction of GHG emissions has become an urgent issue to be resolved in the food system. Many governments and organizations are making great endeavors to alleviate the adverse effect of this phenomenon. In this review, methods to reduce the carbon footprint within the life cycle of a food system are presented from the technical, consumption behavior and environmental policies perspectives. The whole food system including raw material acquisition, processing, packaging, preservation, transportation, consumption, and disposal are covered. Improving management techniques, and adopting advanced technology and equipment are critical for every stage of a food system. Rational site selection is important to alleviate the influence of land use change. In addition, environmental choices of packaging stage, reduction in refrigeration dependence, and correct waste treatment are essential to reduce the total carbon footprint of the production. However, only technical methods cannot radically reverse the trend of climate change, as consumption behaviors present a great deal of influence over climate change. Appropriate purchase patterns and substitution within food product categories by low carbon products can reduce GHG emissions. Development of methods to calculate the carbon footprint of every kind of food and its processing technology enable people to make environmental choice. Policy can shape and cultivate the new code of consumption and influence the direction of emerging technology and science. From political perspectives, government intervention and carbon offset are common tools, especially for carbon tax and a real or implicit price of carbon. Finally, by mitigating the methodologies described above, the rate and magnitude of climate changes can be also reduced to some extent.