Analysis of Sap and liquor from Nipa (Nypa fruticans Wurmb.) fruit stalk using

Introduction

Nipa palm (Nypa fruticans Wurmb) is a plant native to Southeast Asia. It is useful and widely distributed found in the mangrove forests, small lagoons, and estuaries (Tsuji et al., 2011). It is the only member in the genus Nypa (Cui-Lim et al., 2020). Nipa palm is spread throughout the Philippine archipelago and grows along rivers and estuaries affected by tides. It reduces the intensity of high-sea storms and high seas, maintains soil stability, and guards against erosion (Ibrahim et al., 2022). Indigenous people residing in the coastal and estuarine areas used Nipa plants for various purposes. Matured leaves are used for roof thatching and wall-partitioning of dwellings. Edible parts of the plant are its young seeds and buds. The sap of the Nipa fruit stalk undergoes processes that enable sugar, vinegar, and distilled ethanol/liquor to be concentrated (Codas, 2020; Tsuji et al., 2016). Nipa plant produces higher amount of ethanol than Sugar cane plant having 3,350-6,700 L/hectare/year (Tsuji et al., 2011) and 14,300 L/hectare which is more than twice than that of the sugarcane (Puangpee and Chongkhong, 2016). The practice of acquiring distilled ethanol from Nipa has been present in the Philippines since the pre-colonial and Spanish colonial times (Codas, 2020). The Municipality of Gigaquit, Surigao del Norte, Caraga Administrative Region in Mindanao is popular for this practice since the locality has approximately 527 hectares of farmland for Nipa palms. The distilled ethanol/liquor from the naturally fermented Nipa sap (Tuba in local language), is locally referred to as Laksoy (Codas, 2020; Glorious Food, 2023). Currently, the Gigaquit Agra Multi-Purpose Corp. of the Municipal Agriculture Office branded Laksoy as Gigaquit Rhum sold in 375ml Net Content with 80 Proof (40% Alcohol by Volume or ABV). However, the base ingredient for making a traditional Caribbean Rhum is different from Laksoy although both are hard liquor/spirit beverages which have the range of 30-100 Proof, 15%-50% in ABV (Sugue, 2023). Both cannot be considered as wine beverages since liquor/spirits are higher Proof, which are classified below 15% ABV. Rhum is a sub-classification of Rum produced from freshly-pressed sugar cane (Petreycik, 2023) while the Laksoy is produced from Nipa sap (Codas, 2020; Glorious Food, 2023). In order to be fermented, sugarcane juice/molasses must be added with water and yeast for Rhum while there's no need to add yeast to the Nipa sap because of naturally existing yeasts and natural fermentation for Laksoy. Gigaquit Rhum and the traditional light rum are similar due to being colorless liquors. Light rum is sold around 80 proofs (40% ABV) in the United States (ABC Fine Wine & Spirits, 2022). However, for Gigaquit Rhum, undergo aging/maturation during the Nipa sap collection thru the use of traditional bamboo shingle collector and is produced through a single distillation process. The brand name, Gigaquit Rhum, highlights the similarities in production process between Nipa-based liquor and traditional Rhum. This resonates with consumers who are familiar with traditional Rhum but are intrigued by a unique variation made from Nipa Sap. Thus, it has a great economic potential when developed with a good strategy based on research (Ibrahim et al., 2022).

Water in estuarine areas differ in salinity which can be determined in salt parts per million (PPM) and can be classified as fresh water with less than 1,000 PPM, Brackish Water also known as slightly and moderately saline water with 1,000 to 10,000 PPM, or Seawater also known as highly saline water with 30,000 to 40,000 PPM (Woodward, 2023; U.S. Geological Survey, n.d.). Middle-aged Nipa palm gives the best sap yield (Cheablam and Chanklap, 2020). Number of producing days and fruit stalk length are highly correlated with sap yield (Saka et al., 2016). Madigal et al. (2020) developed a Nipa Sap Closed Collection Vessel that preserves the chemical properties of the sap and prevents acceleration of fermentation which yields higher amounts of ethanol. Optimization of Nipa sap for ethanol production was studied by Puangpee and Chongkhong (2016) which researchers determined that the optimum total sugar of the Nipa sap 411 g/L maximum obtained at the initial pH of 4.9 and temperature of 54 °C for 25 minutes. In the study of Limtong et al. (2020), the yeast present in Nipa Palm sap was determined which is S. cerevisae with 100% occurrence frequency and this yeast could playroles in the natural fermentation of the sap. S. cerevisae produced higher ethanol content than P. kudriavzevii (Madigal, 2019). Natural fermentation consumes glucose present in the Nipa sap ranging from 3.4. – 18.8% resulting in whitish color and unpleasant smell (Mateo et al., 2023; Jaraee et al., 2023: Puangpee and Chongkhong, 2016). The production of Nipa Sap has a considerable impact on the consumptive water use of Nipa palms. It was found to be between 893 and 1573 L water/L ethanol, with 90% originating from farms in Nipa. Cui-Lim et al. (2020) studied the presence of a significant amount of distilled ethanol from a fermented Nipa palm fruit through the Litmus, Ester, Iodoform and Flammability test. Ethanol is present after 72 hours of fermentation in all of the tests previously mentioned. During the pot still distillation of the fermented Nipa sap, Ethanol gets evaporated first at 78.4 ℃ followed by Water at 100 ℃. Cooling the alcoholic vapor results to concentrated ethanol distillates with higher alcohol concentration (The Alcohol Pharmacology Education Partnership, n.d). The analysis of Nipa Sap and Rhum from Nipa plants situated on estuarine areas in Gigaquit, Surigao del Norte with difference in salinity was not has not yet been studied. 

This study analyzed Nipa sap and liquor in terms of ethanol (% ABV) and pH from the Nipa plants in the estuary of Barangay Ipil, Gigaquit, Surigao del Norte with Brackish Water and from the Nipa plants in the estuary of Barangay Villafranca, Gigaquit, Surigao del Norte with Seawater. The data from this study will be used as a basis for the standardization of the production of Gigaquit Rhum. 

Explicitly, this study sought to answer the following questions. 

1. What is the average salt part per million (PPM) and pH level in the estuarine Nipa plantation sampling area in Barangay Ipil and Barangay Villafranca? 

2. What is the design of the Nipa Sap Closed Collection Vessel adopted from Madigal et al. (2020) used in the current study?

 3. Is there a significant difference in the amount of Ethanol and pH level of the sap samples from Nipa plants in brackish and Seawater?

 4. Is there a significant difference in the amount of Ethanol and pH level of the sap samples after 3 days (72 hours)?

5. Is there a significant difference in the amount of Ethanol and pH level of the liquor samples from Nipa plants in brackish and Seawater?

 6. What is the average alcohol by volume (ABV) and proof of distilled Ethanol from the sap of Nipa plants in brackish and Seawater?

 Hypotheses H0: 

1. There is no significant difference in the amount of Ethanol and pH level of the sap samples from Nipa plants in brackish and Seawater.

2. There is no significant difference in the amount of Ethanol and pH level of the sap samples after 3 days (72 hours). 

3. There is no significant difference in the amount of Ethanol and pH level of the liquor samples from Nipa plants in brackish and Seawater.

 H1: 

1. There is a significant difference in the amount of Ethanol and pH level of the sap samples from Nipa plants in brackish and Seawater.

2. There is a significant difference in the amount of Ethanol and pH level of the sap samples after 3 days (72 hours).

3. There is a significant difference in the amount of Ethanol and pH content of the liquor samples from Nipa plants in brackish and Seawater. 

Conceptual framework

Nipa palms are aquatic plants (CABI, 2019), wherein the sap samples are harvested from estuarine areas. It is the only palm found in a mangrove forest and is adapted to muddy soils along rivers and estuaries favoring Brackish Water environments (Nwobi, 2020; Tsuji et al., 2011). According to the National Oceanic and Atmospheric Administration (2023), an estuary is a body of water where the river meets the sea affected by tides. Both Barangay Ipil with Brackish Water and Villafranca with Seawater are situated in an estuarine area. These are the independent variables of the study.