Saffron Quality Research Articles

Quality and authenticity of saffron and sensory aspects

Quality and authenticity of saffron and sensory aspects

Effects of Corm Treatment with Cold Plasma and Electromagnetic Field on Growth and Production of Saffron Metabolites in Crocus sativus.

Crocus sativus L. is a widely cultivated traditional plant for obtaining dried red stigmas known as "saffron," the most expensive spice in the world. The response of C. sativus to pre-sowing processing of corms with cold plasma (CP, 3 and 5 min), vacuum (3 min), and electromagnetic field (EMF, 5 min) was assessed to verify how such treatments affect plant performance and the quality and yield of herbal raw materials. The results show that applied physical stressors did not affect the viability of corms but caused stressor-dependent changes in the kinetics of sprouting, growth parameters, leaf trichome density, and secondary metabolite content in stigmas. The effect of CP treatment on plant growth and metabolite content was negative, but all stressors significantly (by 42-74%) increased the number of leaf trichomes. CP3 treatment significantly decreased the length and dry weight of flowers by 43% and 60%, respectively, while EMF treatment increased the length of flowers by 27%. However, longer CP treatment (5 min) delayed germination. Vacuum treatment improved the uniformity of germination by 28% but caused smaller changes in the content of stigma compounds compared with CP and EMF. Twenty-six compounds were identified in total in Crocus stigma samples by the HPLC-DAD method, including 23 crocins, rutin, picrocrocin, and safranal. Processing of Crocus corms with EMF showed the greatest efficiency in increasing the production of secondary metabolites in saffron. EMF increased the content of marker compounds in stigmas (crocin 4: from 8.95 to 431.17 mg/g; crocin 3: from 6.27 to 164.86 mg/g; picrocrocin: from 0.4 to 1.0 mg/g), although the observed effects on growth were neutral or slightly positive. The obtained findings indicate that treatment of C. sativus corms with EMF has the potential application for increasing the quality of saffron by enhancing the amounts of biologically active compounds.

Yield and quality of saffron (Crocus sativus L.) in response to priming treatments and water deficit

Despite being the most expensive spice, saffron is generally exposed to drought stress during its life cycle. The application of some effective compounds in the plants, can make it strong against environmental stresses such as water deficit. Therefore, the effect of saffron corm priming on the quantitative, qualitative, and physiological responses of this crop under drought stress was investigated in a split-plot experiment as a randomized complete block design with three replicates in two experimental years, 2022 and 2023. The treatments of the on-field experiment included 50 % Field capacity (FC) (equal to 2500 m3ha−1) and 70 % FC (equal to 3800 m3 ha−1) as the main plot and pretreatments (Corm priming) at six levels of KNO3 (3:1000), Indole-3-acetic acid (1 mg l−1), Gibberellin (300 ppm), Silicon dioxide nanoparticles (100 ppm), Hydro-priming (distilled water) and non-priming (control) as sub-plots. The results revealed the increase of petal and stigma dry weights with the application of IAA priming agents under 70 % FC irrigation as compared to 50 % FC. Based on the findings, the petal dry weights decreased, under 50 % FC in the growing season (2022 and 2023), as compared to 70 % FC conditions. Water use efficiency increased significantly with the use of IAA compared to other treatments in the second year. Water deficit led to an increase in leaf proline content and total soluble sugar. The amounts of picrocrocin improved by 5.6 % with decreasing irrigation water from 70 % to 50 % FC in both experimental years. Moreover, the highest amounts of safranal were gained when corms were exposed to IAA. Priming with IAA increased the dry weight of daughter corms compared to other priming treatments. The N and P absorbed by saffron corm decreased to 29.2 % and 28.6 % at 70 % and 50 % FC, respectively. The highest K+ uptake was recorded with the application of IAA under 70 % FC. Overall, this work indicated that an increase in saffron yield and the quality of flowers is associated with an increase in dry weight of daughter corms, ion absorption in corms and the activity of non-enzymatic defense system caused by the application of IAA under different soil moisture.

A novel mutation in non-constitutive lycopene beta cyclase (CstLcyB2a) from Crocus sativus modulates carotenoid/apocarotenoid content, biomass and stress tolerance in plants.

Mutation at A126 in lycopene-β-cyclase of Crocus (CstLcyB2a) sterically hinders its binding of δ-carotene without affecting lycopene binding, thereby diverting metabolic flux towards β-carotene and apocarotenoid biosynthesis. Crocus sativus, commonly known as saffron, has emerged as an important crop for research because of its ability to synthesize unique apocarotenoids such as crocin, picrocrocin and safranal. Metabolic engineering of the carotenoid pathway can prove a beneficial strategy for enhancing the quality of saffron and making it resilient to changing climatic conditions. Here, we demonstrate that introducing a novel mutation at A126 in stigma-specific lycopene-β-cyclase of Crocus (CstLcyB2a) sterically hinders its binding of δ-carotene, but does not affect lycopene binding, thereby diverting metabolic flux towards β-carotene formation. Thus, A126L-CstLcyB2a expression in lycopene-accumulating bacterial strains resulted in enhanced production of β-carotene. Transient expression of A126L-CstLcyB2a in C. sativus stigmas enhanced biosynthesis of crocin. Its stable expression in Nicotiana tabacum enhanced β-branch carotenoids and phyto-hormones such as abscisic acid (ABA) and gibberellic acids (GA's). N. tabacum transgenic lines showed better growth performance and photosynthetic parameters including maximum quantum efficiency (Fv/Fm) and light-saturated capacity of linear electron transport. Exogenous application of hormones and their inhibitors demonstrated that a higher ratio of GA4/ABA has positive effects on biomass of wild-type and transgenic plants. Thus, these findings provide a platform for the development of new-generation crops with improved productivity, quality and stress tolerance.

Evaluation of Saffron Quality Using Rapid Quantitative Inspection Technology with Near-Infrared Spectroscopy.

A predictive model utilizing near-infrared spectroscopy was developed to estimate the loss on drying, total contents of crocin I and crocin II, and picrocrocin content of saffron. Initially, the LD values were determined using a moisture-ash analyzer, while HPLC was employed for measuring the total contents of crocin I, crocin II, and picrocrocin. The near-infrared spectra of 928 saffron samples were collected and preprocessed using first derivative, standard normal variable transformation, detrended correction, multivariate scattering correction, Savitzky-Golay smoothing, and mean centering methods. Leveraging the partial least squares method, regression models were constructed, with parameters optimized through a selective combination of the above six preprocessing methods. Subsequently, prediction models for loss on drying, total contents of crocin I and crocin II, and picrocrocin content were established, and the prediction accuracy of the models was verified. The correlation coefficients and root mean square error of loss on drying, total contents of crocin I and crocin II, and picrocrocin content demonstrated high accuracy, with R2 values of 0.8627, 0.8851, and 0.8592 and root mean square error values of 0.0260, 0.0682, and 0.0465. This near-infrared prediction model established in the present study offers a precise and efficient means of assessing loss on drying, total contents of crocin I and crocin II, and picrocrocin content in saffron and is useful for the development of a rapid quality evaluation system.

Time-of-Flight Secondary Ion Mass Spectrometry Coupled with Unsupervised Methods for Advanced Saffron Authenticity Screening.

Saffron, renowned for its aroma and flavor, is susceptible to adulteration due to its high value and demand. Current detection methods, including ISO standards, often fail to identify specific adulterants such as safflower or turmeric up to 20% (w/w). Therefore, the quest continues for robust screening methods using advanced techniques to tackle this persistent challenge of safeguarding saffron quality and authenticity. Advanced techniques such as time-of-flight secondary ion mass spectrometry (TOF-SIMS), with its molecular specificity and high sensitivity, offer promising solutions. Samples of pure saffron and saffron adulterated with safflower and turmeric at three inclusion levels (5%, 10%, and 20%) were analyzed without prior treatment. Spectral analysis revealed distinct signatures for pure saffron, safflower, and turmeric. Through principal component analysis (PCA), TOF-SIMS effectively discriminated between pure saffron and saffron adulterated with turmeric and safflower at different inclusion levels. The variation between the groups is attributed to the characteristic peaks of safflower and the amino group peaks and mineral peaks of saffron. Additionally, a study was conducted to demonstrate that semi-quantification of the level of safflower inclusion can be achieved from the normalized values of its characteristic peaks in the saffron matrix.

Effects of different microbial agent applications on the growth and quality of saffron (Crocus sativus L.) cormels

Saffron (Crocus sativus L.) is a bulbous flower whose dried stigmas are used as a herbal medicine and as a spice. Saffron is cultivated worldwide, but corm degradation is an important factor affecting its yield and quantity. This study investigated the effects of three different microbial agents (Bacillus megaterium, Brevibacillus laterosporus, Paenibacillus mucilaginosus) on the growth and quality of saffron cormels. Both the weight and circumference of the cormels were significantly increased in response to microbial agent treatment. Measurements of the physiological and biochemical characteristics of the cormels as well as the flowering traits showed that the starch and protein contents as well as the flowering rate and stigma yield increased significantly after the application of the three microbial agents. Analyses of soil physicochemical properties and microbial populations revealed increases in the soil potassium content and a significant alteration in the soil microbial community structure in response to treatment. Our results showed that the application of three microbial agents enhances the growth, nutritional status and health of saffron cormels and improves the soil environment during saffron corm cultivation. Paenibacillus mucilaginosus also increased the accumulation of crocins and picrocrocin in stigmas. Our results provide the theoretical and practical knowledge needed to reduce corm degradation and to improve saffron corm cultivation.

Improvement in Productivity and Quality of Soilless Saffron Crops by Implementing Fertigation

Saffron cultivation is important in global agriculture and is mainly flourishing in Mediterranean climates. Although it originated in Asia Minor, it is widely grown in regions such as Iran, India, Spain, Morocco, Greece, and Italy. Labour-intensive harvesting, mainly by hand, characterises its production and offers substantial employment opportunities in cultivating areas. However, traditional saffron-producing countries such as Spain, Italy, and Greece have witnessed declining production due to labour demands and competition from low-wage countries. Mechanization remains unfeasible due to the delicate nature of the plant. To revitalise saffron cultivation, efforts have been focused on reducing labour costs, improving productivity, and improving quality through innovative techniques, such as soilless crops. In this study, the productivity and quality of saffron was evaluated in a soilless culture and three fertigation doses were evaluated: a control, consisting of Sonneveld and Voogt’s standard nutrient solution, and two treatments with two supplemented solutions, 30% K and 30% Ca. The results indicated that the solution with 30% K obtained higher corm productivity, as well as better quality saffron, as all the products of this treatment were included in Category I according to the ISO 3632 standard, while the quality of saffron grown with the control solution was lower.

Saffron corm sorting and rot treatment strategy for productivity enhancement for precision agriculture

One of the most economical and precious spices ever known is saffron. It has innumerable pharmaceutical applications, and its cultivation is limited to certain topographic regions throughout the world. Although efforts are continuously being made to increase productivity and increase the area under cultivation, there are multiple factors leading to its low production. Corm size is one of the major factors affecting the quality and production of saffron. The more the corm size for a plantation, the better the yield of the crop. This can pose a serious threat to saffron cultivators who are not able to get good quality corms and sort quality corms from infected ones. Additional factors affecting saffron cultivation include attack by fungus leading to corm rots and sclerotineal disease. In this paper, IoT (Internet of Things) has been used to provide an energy-efficient, ready-to-use, reliable, and user-friendly solution for corm sorting and treatment before sowing to promote quality, better yield and minimized wastage due to corm rots. After sorting the corms, they are treated with 0.2% of tiabendazole fungicide solution and dried, before sowing and for long-term storage. Firstly, sorting and treatment system for the saffron corms processing as per weight is proposed. First two-layer cleaning mechanism to remove foreign substances, then three-step treatment has been applied to remove microorganisms. An automated conveyor system equipped with IoT devices was used for sorting and treating saffron corms. Different energy efficient LPWA (Low Power Wide Area) and LTE (Long Term Evolution) technologies used in the framework, for communication are NB-IoT (Narrow Band IoT) and LoRa (Long Range Radio).

Comparison quality parameters of saffron (Crocus sativus L.) produced in Herat, Afghanistan and Torbat Heydarieh, Iran

Saffron Crocus sativus L. (Iridaceae) is one of the most valuable and expensive medicinal plants in the world. In order to compare the quality characteristics of saffron in Afghanistan and Iran, samples of dried C. sativus from different saffron-producing regions of Herat province (Afghanistan) and Torbat Heydarieh county (Iran) were collected in the year 2021. The experiment was analyzed in GLM format and Nested method with three replications. The samples of saffron produced from seven different districts of Herat province in Afghanistan, including Injil, Karukh, Guzara, Pashtun Zarghun, Zendeh Jan, Ghoryan, Obeh and nine saffron-producing villages (Fakhrabad, Kadkan, Nasar, Ghaleno, Feizabad, Khorgh, Abrood, Benhang, Shadmehr) of Torbat Heydarieh county in Iran were examined. The results showed that the effect of country and region (districts and villages) on the quality traits of saffron (crocin, picrocrocin and safranal) was significant. Moreover, the comparison of the mean values indicated the presence of significant differences in the qualitative characteristics of saffron among the different investigated villages of Torbat Heydarieh. The saffron produced in Afghanistan had the highest amount of crocin (on average 279.1 ɷ 440nm) and picrocrocin (on average 101 ϕ 257nm), while the highest value of safranal (on average 34.2 θ 330nm) was observed in saffron samples produced in Iran. The highest amount of the above quality traits belonged to the saffron of Zendeh Jan Herat region 5 (Af5, crocin: 303 ɷ 440 nm, picrocrocin: 106 ϕ 257 nm, safranal: 33 θ 330 nm), while the five Torbat Heydarieh villages had the lowest quality of saffron (Ir5, crocin: 164 ɷ 440nm, picrocrocin: 71 ϕ 257 nm, safranal: 34 θ 330 nm). In the comprehensive analysis of saffron-producing regions in Afghanistan and Iran, in terms of the qualitative attributes (crocin, picrocrocin, and safranal) it was evident that regions 1 to 6 in Herat, Afghanistan (Af1, Af2, Af3, Af4, Af5, Af6) and the Abrood village of Torbat Heidarieh, Iran (Ir7) formed a distinct cluster, demonstrating superior quality compared to other regions. Furthermore, with the exception of the Feizabad village of Torbat Heydarieh (Ir5), all examined samples surpassed the saffron ISO international standard and were categorized as first-grade quality. The exceptional quality of Herat saffron from Afghanistan is likely attributable to the unique geographical features, virgin lands, and specific climatic conditions across diverse cultivation areas.

The subsurface application of pistachio waste compost and foliar spraying of organic matter can induce the flower yield and the quality of saffron (Crocus sativus L.) corms affected by restricted nutrient conditions

Correct use of organic waste in the form of composting can play a constructive role in reducing environmental pollution and increasing saffron sustainable production. Recently, pistachio waste compost has been considered as a soil conditioner, especially in arid and semi-arid areas. Along with improving the organic structure, foliar application of amino acids through the recommendation of reputable companies is another sustainable solution that can further strengthen the relationship between trade and agriculture. The current study was conducted in Anbari Agricultural Seeds Company, Mashhad, Iran during 2019-2021. The experiment was performed with three replicates based on a randomized complete block design arranged in factorial-split including 12 main plots [Organic fertilizer (control, pistachio compost (P), wheat straw (W), cow manure (M), P+W, and P+M) × Foliar spraying (control and 2 L. ha−1 DRIN: a commercial organic compound)] and 2 sub-plots (first and second sampling). The minimum number of saffron flowers and stigma weight were observed under no-organic fertilizer; while all organic sources led to increase these traits. The values increased by 27% and 31%, respectively, resulting pistachio compost compared to control treatment. Applying organic sources resulted in a higher crocin and safranal. At the same time, foliar spraying had a significant effect in increasing crocin and safranal concentrations. Organic fertilizers and foliar spraying caused a significant effect in terms of N, P, and K concentration in daughter corms. when control treatment was considered, foliar spraying increased sucrose by 24% compared to non-spraying. Furthermore, sucrose content was recorded to be improved following all organic amendments. Similar responses were observed regarding arginine, glutamic acid, alanine, and aspartic acid. Overall, applying pistachio compost concurrent with spraying of DRIN is recommended for saffron sustainable production, especially under nutrient-restricted conditions.

Saffron spice quality in response to integrated nutrient management under lesser Himalayan conditions of Rawalakot Azad Jammu & Kashmir

Integrated nutrient management is an environment friendly approach of plant nutrition being used for crop productivity and improvement in soil quality on sustainable basis. A three-year multi-location experiment was conducted to estimate the spice quality of saffron subjected to the integration of organic and inorganic nitrogen sources. At each location, the experiment was laid out in randomized complete block design. The treatments were T1 = control (without organic/inorganic N source/amendment); T2 = Full recommended nitrogen (i.e. urea fertilizer @ equivalent to 100 kg N ha−1; UN100); T3 = Poultry manure (PM) @ equivalent to 100 kg total N ha−1 (i.e. PM100); T4 = Farm yard manure (FYM) @ equivalent to 100 kg total N ha−1 (i.e. FYM100); T5 = PM50+FYM50; T6 = UN75 + PM25; T7 = UN50 + PM50; T8 = UN25 + PM75; T9 = UN75 + FYM25; T10 = UN50 + FYM50; T11 = UN25 + FYM75 and T12 = UN50 + PM25+ FYM25. Among treatments, poultry manure (100%) and urea nitrogen with poultry manure (UN50 + PM50) significantly affected the quality attributes of saffron. On the other hand, among sites, the crocin, picrocrocin and saffranal contents were in order of Khaigala (23.81% crocin, 20.01% picrocrocin and 0.27% saffranal) >Trarkhel (19.04% crocin, 16.99% picrocrocin and 0.25% saffranal) and > Abbaspur (17.80% crocin, 15.45% picrocrocin and 0.23% saffranal). Similarly, among years, the crocin, picrocrocin and saffranal contents were significantly higher in the third year compared to the first and second year. In conclusion, the integration of organic nitrogen sources with inorganic nitrogen has the potential to improve saffron quality.

Application of the relative molar sensitivity method using GC-FID to quantify safranal in saffron (Crocus sativus L.).

Safranal is one flavor component of saffron, which is used as a spice, food additive, and crude drug. In ISO3632, safranal is defined as the compound that contributes to the quality of saffron, and many quantitative determination methods for safranal have been reported. However, safranal is volatile and degrades easily during storage, and an analytical standard with an exact known purity is not commercially available, making it difficult to quantify accurately the content of safranal in saffron. Here, we developed a method for quantifying safranal using relative molar sensitivity (RMS), called the RMS method, using a GC-flame ionization detector (GC-FID). We determined the RMS of safranal to 1,4-bis(trimethylsilyl)benzene-d4, a certified reference material commercially available, by a combination of quantitative NMR and chromatography. Using two GC-FID instruments made by different manufacturers to evaluate inter-instrument effect, the resultant RMS was 0.770, and the inter-instrument difference was 0.6%. The test solution, with a known safranal concentration, was measured by the RMS method, with an accuracy of 99.4-101%, repeatability of 0.81%, and reproducibility of 0.81-1.3%. Given the ease of degradation, high volatility, and uncertain purity of safranal reagents, the RMS method is a more accurate quantification approach compared to the calibration curve method and methods based on absorption spectrophotometry. Moreover, our findings revealed that the GC-FID makeup gas affected the RMS and quantitative values.

Improving the Accuracy of Saffron Adulteration Classification and Quantification through Data Fusion of Thin-Layer Chromatography Imaging and Raman Spectral Analysis.

Agricultural crops of high value are frequently targeted by economic adulteration across the world. Saffron powder, being one of the most expensive spices and colorants on the market, is particularly vulnerable to adulteration with extraneous plant materials or synthetic colorants. However, the current international standard method has several drawbacks, such as being vulnerable to yellow artificial colorant adulteration and requiring tedious laboratory measuring procedures. To address these challenges, we previously developed a portable and versatile method for determining saffron quality using a thin-layer chromatography technique coupled with Raman spectroscopy (TLC-Raman). In this study, our aim was to improve the accuracy of the classification and quantification of adulterants in saffron by utilizing mid-level data fusion of TLC imaging and Raman spectral data. In summary, the featured imaging data and featured Raman data were concatenated into one data matrix. The classification and quantification results of saffron adulterants were compared between the fused data and the analysis based on each individual dataset. The best classification result was obtained from the partial least squares-discriminant analysis (PLS-DA) model developed using the mid-level fusion dataset, which accurately determined saffron with artificial adulterants (red 40 or yellow 5 at 2-10%, w/w) and natural plant adulterants (safflower and turmeric at 20-100%, w/w) with an overall accuracy of 99.52% and 99.20% in the training and validation group, respectively. Regarding quantification analysis, the PLS models built with the fused data block demonstrated improved quantification performance in terms of R2 and root-mean-square errors for most of the PLS models. In conclusion, the present study highlighted the significant potential of fusing TLC imaging data and Raman spectral data to improve saffron classification and quantification accuracy via the mid-level data fusion, which will facilitate rapid and accurate decision-making on site.

Beneficial microorganisms: a sustainable horticultural solution to improve the quality of saffron in hydroponics

Saffron (Crocus sativus L.) is the most expensive spice in the world. Its organoleptic properties are mainly dictated by the apocarotenoids crocins (dyeing capacity), picrocrocin (pleasant taste), and safranal (scent). Cultivation of saffron in controlled conditions with beneficial microorganisms may increase its profitability. In this study saffron was grown in hydroponics under a greenhouse with the PGPR Bacillus megaterium CB97032 and Paenibacillus durus CB1806 (Pgpr treatment), and the AMF Rhizophagus intraradices (Myc treatment), alone or mixed (Mix treatment). The influence exerted during all crop phases on flowering trend, flower and spice yield, secondary metabolites, ecophysiological traits, and corm production was investigated, with the hypothesis that microbial synergy would have more positively affected these parameters. All the bioinoculants did not positively influence flower and spice yield, but enhanced the content of safranal (up to +96% in all the treated plants). When mixed, the PGPR and AMF improved the total phenolic content (+19%) of the saffron spice. Even if no differences emerged from the ecophysiological analysis, the corm yield was improved for the inoculated plants. The single-type bioinoculants allowed to obtain a higher number of replacement corms (up to +13% for the Myc plants) without reducing their weight, but lowering their size. When mixed, the size of the corms was restored. Together, the PGPR and AMF also increased the corm weight (+24%) of the largest corm fraction (> 1.5 cm). Thus, the bioinoculants may have stimulated the secondary metabolism of the plants by improving quality traits, rather than having acted as biofertilizers by increasing yield, at least during flowering. Overall, AMF and PGPR were proved to be a sustainable horticultural solution in hydroponics to improve the quality of saffron, especially when applied in mixed formulations.

Effects of total daily light integral from blue and broad-band red LEDs on flowering of saffron (Crocus sativus L.)

Present indoor cultivation of saffron (Crocus sativus L.) only depends on artificial planting experience, so that flower number and stigma yield are seriously affected in case of cloudy or rainy days and temperature changes. In this study, a luminaire was used at 10-h photoperiod combined 450 nm blue LEDs with 660 nm broad-band red LEDs, which respectively had full width at half maximum (FWHM) of 15 nm and 85 nm, in a ratio of blue: red: far-red light = 20%: 62%: 18%. The influence of total daily light integral (TDLI) was evaluated on flowering characteristics, stigma quality, as well as leaf morphological characteristics. The results showed that flower number, daily flowering proportion, stigma dry weight and crocetin esters content were significantly correlated with TDLI (P < 0.01). The increasing TDLI could slightly promote leaf width and leaf area beyond buds, but had no significant effect on bud length and leaf length. Both the average flower number per corm and dried stigma yield was the highest under the 150 mol m−2 TDLI treatment, up to 3.63 and 24.19 mg respectively. The former was 0.7 more than that under original natural light treatment, while the later was 50% higher. Totaling, combining blue LEDs with a broad-band red LEDs of the 150 mol m−2 TDLI was the most favorable condition for flower number and stigma quality of saffron in this study.

Effects of Chelated Iron (Eddha-Fe) Treatments on Corm And Stigma Quality in Saffron (Crocus Sativus L.)

Effects of different doses of chelated iron (EDDHA-Fe) on the yield and quality of saffron leaf, corm and stigma were investivated. The highest weight of harvested corms was obtained when treated with 2 g of iron chelate per corm, 366.57 g, and the highest number of corm was obtained when treated with 4 g of iron chelate per corm, 73.00 g. When the effects of the iron chelate treatments on the quality of the stigma studied, it was found that the treatment with 2 g of iron chelate per corm gave a yield of dry stigma 754.00 mg and the highest average amount of safranal of 1386.50 mg/kg. The treatment with iron chelate had a positive effect in increasing the yield of the corm, the yield of dry stigma, and the quality of stigma saffron. Bangladesh J. Bot. 52(1): 97-103, 2023 (March)

Improved growth and quality of saffron (Crocus sativus L.) in the field conditions through inoculation with selected native plant growth-promoting rhizobacteria (PGPR)

The use of bioresources such as bio-fertilizers especially those containing plant growth promoting rhizobacteria (PGPR), may be a strategy for sustainable agriculture that respects the environment while ensuring optimal plant growth. The objective of this study was to investigate the effects of selected PGPR strains on the growth, yield and quality of saffron. The bacteria tested were isolated from the saffron rhizosphere and selected for important plant beneficial activities (phosphate solubilization, siderophore, and auxin production). The best strains were identified by 16S rRNA gene sequence analysis. Strains S11P1 and S11A1a were identified as Rahnella aquatilis, while strain S12S4 belonged to the species Variovorax paradoxus. An inoculation field experiment was conducted in a 1575 m2 field area in Taliouine (Morocco). Four different inoculants were set-up: the three single selected strains and their mixture. Using the PGPR isolates as inoculum affects positively different saffron plant parameters, such as the number of leaves (28.87 ± 6.1 vs. 22.47 ± 8.19 for control treatment) and chlorophyll content. Underground parts, in particular, daughter corms production was significantly increased about 1.91 times more than the control. In addition, the quality of inoculated saffron was in accordance with the category I specifications (Crocin > 200, Picrocrocin > 70 and Safaranal >20). Overall these results bode well the possibility of using these rhizobacteria, and specially the treatment T2 (Rahnella aquatilis S11P1), as effective biofertilizers for saffron organic cultivation.

Smart Framework for Quality Check and Determination of Adulterants in Saffron Using Sensors and AquaCrop

Saffron is a rare and valuable crop that is only cultivated in specific regions with suitable topographical conditions. To improve saffron cultivation, it is crucial to monitor and precisely control the crop’s agronomic variables over at least one growth cycle to create a fully automated environment. To this end, agronomic variables in the Punjab region of India were analyzed and set points were calculated using third-order polynomial equations through the application of image processing techniques. The relationship between canopy cover, growth percentage, and agronomic variables was also investigated for optimal yield and quality. The addition of adulterants, such as turmeric and artificial colorants, to saffron is a major concern due to the potential for quality compromise and fraud by supply chain vendors. Hence, there is a need for devising an easy, reliable, and user-friendly mechanism to help in the detection of adulterants added to the saffron stigmas. This paper proposes an automated IoT-based saffron cultivation environment using sensors for determining set points of agronomical variables. In addition, a sensor-based chamber has been proposed to provide quality and adulteration checks of saffron and to eliminate product counterfeiting. The AquaCrop simulator was employed to evaluate the proposed framework’s performance. The results of the simulation show improved biomass, yield, and harvest index compared with the existing solutions in precision agriculture. Given the high value and demand for saffron, ensuring its purity and quality is essential to sustain its cultivation and the economic viability of the market.

Quality of Saffron in Oman Markets

Saffron is the most expensive spice in the world, it is highly valued as a culinary spice for its flavor and color properties. Since saffron is an expensive product, it is cheated by the dealers, therefore, quality control of saffron is important for the spice industries and also the consumers. This study aims to evaluate the saffron quality in Omani markets according to the ISO standard. A total of 21 saffron samples were examined; 2 in powder form and 19 in filaments. The samples of saffron were purchased from different hyper-markets and local markets in Muscat, Oman. Saffron’s commercial value is determined according to the ISO standard which include moisture, ash, acid insoluble ash, extract %, sulfuric test, artificial colors, spectrum, Flavor, aroma and color. The saffron samples were in line with standard in terms of moisture, ash, acid insoluble ash and extract %. The two powder saffron samples failed in sulfuric, spectrum and flavor tests. From the 19 samples of saffron filament, three samples were failed to achieve the flavor and color limits required by the standard. This failure to standard quality could be due to poor processing condition such as drying and packaging or due to adulteration. The standard parameters could not distinguish between low quality and adulteration due to its limited and unspecific parameters. Therefore, we recommend improving the saffron standard with parameters targeting adulteration.